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Title: Neogene and late Paleogene record of Himalayan orogeny and climate: a transectacross the Middle Bengal Fan.
Proponent(s): Christian France-Lanord1, Volkhard Spiess2, Peter Molnar3 and Joseph R Curray4
1: CRPG-CNRS, 15 rue Notre Dame des Pauvre, 54501 Vandoeuvre, France, [email protected]
2: Dept. of Earth Science, Bremen University Klagenfurter Str., 28359 Bremen, Germany [email protected]
3, Dept. Geological Sci. CIRES-UC Boulder Campus Box 399 Boulder, CO80309 USA [email protected], Scripps Institution of Oceanography, La Jolla, CA 92093-0220 - USA [email protected]
Keywords:(5 or less)
Turbidites , Monsoon, Channel levee, Source to Sink Area: Bay of Bengal
Contact Information:Contact Person: Christian France-Lanord
Department: CRPGOrganization: CNRS
Address 15 rue Notre Dame des Pauvres BP 20, 54501 Vandœuvre les Nancy - FRANCETel.: 33 (0) 83 59 42 20 Fax.: 33 (0) 83 51 17 98
E-mail: [email protected]
Permission to post abstract on iSAS Web site: Yes No
Abstract: (400 words or less)
We propose drilling a transect of holes in the Bay of Bengal to address interactions among the growth of theHimalaya and Tibet, the development of the Asian monsoon, and processes affecting the carbon cycle and globalclimate. Because sedimentation in the Bengal Fan responds to both climate and tectonic processes, its terrigenoussediment records the past evolution of both the Himalaya and regional climate. The histories of the Himalaya/Tibetan system and the Asian monsoon require sampling different periods of time with different levels of precision.Accordingly, we propose a transect of six holes in the fan at 8°N with two complementary objectives :(1) The early stages of Himalayan erosion, which will bear on the India-Eurasia collision and the development ofthe Himalaya and Tibet as topographic features. We propose a deep hole (MBF-3A ~1500m) in the west flank ofthe Ninetyeast Ridge where a reflector interpreted as a Paleocene-Eocene unconformity could be reached at areasonable depth.(2) The Neogene development of the Asian monsoon and its impact on sediment supply and flux. We propose aneast-west transect at 8°N composed of MBF-3A plus two drill sites, each of ~900 m penetration (MBF-1A and 2A),to reach sediment at least as old as 10-12 million years. Records from the Arabian Sea and the Indian subcontinentsuggest that at ~7-8 Ma the intensity of the monsoon increased and C4 plants expanded. Moreover, they appear tobe linked to changes in the erosional regime as recorded by Leg 116, and possibly to the tectonic evolution ofsoutheast Asia. This transect will allow the study of the extent to which a strengthening of the monsoon encom-passed the Bay of Bengal, where increased rainfall, not strengthened wind characterize the monsoon, and will allowquantitative studies of the interrelations of climate change and sediment accumulation.In addition three Sites (MBF-4A to -6A) will allow to determine, how the depocenter migrates across this transectduring the last million year and to ensure complete recovery of channel-derived terrigenous material through thistime interval.
iSAS/IODP Proposal Cover SheetNew Revised Addendum
Above For Official Use Only
Scientific Objectives: (250 words or less)
This proposal addresses the general objective to understand how the Himalayan-Tibet orogenesis interacts withthe earth climate. This includes forcing of the climate due to paleogeographic evolution and atmospheric CO2
uptake as well as retroaction of the monsoon climate on the tectonic via erosion. Because the Bengal Fan hasaccumulated most of the Himalayan erosion flux since the continental collision, it represents the most completerecord of both the uplift and erosion history of the Himalaya and of the monsoon climate. Sediments willdocument (1) uplift history through erosional flux and deposition patterns and detailed geochronology ofminerals, (2) Himalayan evolution from isotopic tracing of particle origin and age, and (3) environmental andclimate conditions through sediment granulometry, mineralogy and geochemistry, organic matter compositionand δ18O of microfossils. A reliable quantification of erosional fluxes over the Neogene is essential to assess therole of the Himalayan erosion on the global carbon cycle. The Leg 116 in the distal fan has shown majorvariations of these proxies over the Neogene and the proposed Leg should allow to test their regionalrepresentativeness. The proposed transect at 8°N will allow to construct a complete record of the NeogeneHimalayan erosion and monsoon and to complete the present record of Himalayan erosion beyond the Miocene.
Proposed Sites:Penetration (m)
Site Name Position
Water
Depth (m)
Sed Bsm TotalBrief Site-specific Objectives
MBF-1A
MBF-2A
MBF-3A
MBF-4A
MBF-5A
MBF-6A
8°0.42’N / 86°16.97E
8°0.4N / 87°38'E
8°0.4N / 88°41'E
8°0.4N / 86°47.9E
8°0.4N / 87°10.9E
8°0.4N / 88°06.6E
3747
3678
3620
3694
3687
3672
900
900
1500
300
300
300
0
0
0
0
0
0
900
900
1500
300
300
300
Neogene historyDepocenter migration
Neogene historyDepocenter migration
Neogene historyEarly fan historyDepocenter migrationDepocenter migration
Depocenter migration
Depocenter migration
Proposal 552-full3
Proposal 552-full3 - Neogene and late Paleogene record of Himalayan orogeny and climate:a transect across the Middle Bengal Fan.
List of potential reviewers :
Dr Jean Philippe Avouac [email protected] de détection géophysiqueCEA BP 1291680 Bruyères-le-Chatel - France
Pr. Douglas Burbank [email protected]. of Geosciences539 DeikePennsylvania State UniversityUniversity Park, PA 16802, USA
Pr. Peter Copeland [email protected] of GeosciencesUniversity of HoustonHouston, Texas 77204-5503 USA
Pr. Jean-Claude DuplessyLSCE-Vallée, Bât. 12, avenue de la Terrasse,F-91198 GIF-SUR-YVETTE CEDEX - France
Pr. Philip England [email protected] of OxfordDepartment of Earth SciencesPrks Road - Oxford, OX1 3PR (GB)
Pr. Mark Harrison [email protected]. of Earth and Space Sciences and IGPP3652 Geol Bldg - UCLALos Angeles CA 90024
Dr. Dick KroonDepartment of Geology and Geophysics-Grant InstituteUniversity of EdinburghWest Mains RoadEdinburgh EH9 3JW - United Kingdom
Dr. Herman Kudrass [email protected] / Stilleweg 2D-30655 Hannover, Germany
Pr. Warren Prell [email protected] of Geological SciencesBrown University - Box 1846Providence, RI 02912 - U.S.A
Pr. Jay Quade [email protected] of GeosciencesThe University of ArizonaTucson, Arizona 85721-0077 - USA
Dr. Gilles Ramstein [email protected] des Sciences du Climat et de l’EnvironnementBat 709 CEA-DSM, Orme des Merisiers F 91191 Gif-sur-Yvette cedex, France
1: CRPG-CNRS, 15 rue Notre Dame des Pauvre, 54501 Vandoeuvre, France, [email protected]: Dept. of Earth Science, Bremen University Klagenfurter Str., 28359 Bremen, Germany [email protected], Dept. Geological Sci. CIRES-UC Boulder Campus Box 399 Boulder, CO80309 USA [email protected] 4, Scripps Institution of Oceanography, La Jolla, CA 92093-0220 - USA
Proposal 552-full3
Neogene and late Paleogene record of Himalayan orogeny and climate: a transect across the Middle Bengal Fan
552-full3 – Bengal Fan - Oct.
1
Neogene and late Paleogene record of Himalayan orogeny and climate: a transect across the Middle Bengal Fan.
Table of content
Preface 2
I – INTRODUCTION 3
II - DRILLING OF BENGAL FAN: DISCUSSION OF OBJECTIVES 4
CALIBRATION OF CHANGES AT 7-8 MA AND SINCE THAT TIME 5
SAMPLING OF THE OLDEST SEDIMENT OF THE FAN 8
SPATIAL DEPOCENTER VARIABILITY 9
FORCING OF THE CARBON CYCLE AND CLIMATE 10
COMPARISON OF THE BENGAL AND INDUS FANS 11
RELEVANCE TO THE INITIAL SCIENCE PLAN OF IODP 12
III SUMMARY OF PROPOSED SITES AND DRILLING STRATEGY 12
RELEVANCE OF PROPOSED SITES TO SCIENTIFIC OBJECTIVES 16
SITE SURVEYS 18
SAFETY 18
SUMMARY OF SEDIMENTOLOGICAL TRACERS TO BE USED 19
REFERENCES 21
552-full3 – Bengal Fan - Oct.
Neogene and late Paleogene record of Himalayan orogeny and climate:
a transect across the Middle Bengal Fan.
This project for drilling in the
PPG of ODP, which selected the Ben
tectonics links in orogenic environ
comments of the SSEPanels. Their
reduce the study of the channel-levee s
718 in the distal fan for the lon
recommendations we focussed the Le
For a long-term record we suggest a h
We withdrew the channel-levee archi
the transect to determine depocenter m
The present proposal is now foc
pre-Neogene sedimentary record. Thi
system and its dominant processes, bo
that understanding the channel-levee a
interpreting the older records. We view
that will be covered by a pre-propos
different sedimentary environments, to
Because the document limitatio
knowledge on the Bengal fan and
information here. Since this proposal
domains, however, reviewers and int
covers the following topics: (1) the B
the Tibetan plateau and the Himalay
ftp://www.crpg.cnrs-nancy.fr/pub/cfl/B
2
Preface
Bengal Fan was initiated by the Climate and Tectonic
gal Fan as a principal objective to study the climate -
ments. This second revised version addresses the
most important recommendation was to withdraw or
ystem in the upper part of the Fan and on choice of Site
g-term record objective. In order to follow these
g on the transect area in the middle of the Bengal Fan.
ole on the west flank of the Ninetyeast Ridge at 8° N.
tecture objectives and we added three shallow holes on
igration.
ussed on the long-term variations in the Neogene and
s, however, relies on a better knowledge of the whole
th in the fan and on land. In particular, we emphasize
rchitecture and its time scale is a fundamental issue for
this proposal also as part of a more extended initiative
al for multiplatform drilling in the Bay of Bengal in
be submitted in October 2001.
ns do not allow a detailed presentation of background
Himalayan history, we have reported only limited
relates knowledge from both continental and oceanic
erested readers can find supplemental information that
engal fan and its seismic framework, (2) the growth of
a, and (3) the development of the Asian monsoon at
engalSummary.pdf .
552-full3 – Bengal Fan - Oct.
3
I – INTRODUCTION
Among regions of the world where tectonics and climate interact, southern Asia seems
to illustrate the possible influences of one on the other more dramatically than any other
region. The high elevation of the Tibetan Plateau and the rapid rise from the lowlands of
northern India across the Himalaya profoundly affect both the average temperature structure
of the atmosphere responsible for the seasonal winds and the localization of precipitation that
characterize the south Asian monsoon. Concurrently, the large seasonal variations in
precipitation along the Himalaya affect erosion rates. Yet, if the Tibetan Plateau and the
Himalaya have influenced climate during Cenozoic time, the evidence suggesting such an
influence is wholly inadequate to understand quantitatively how the development of these
geographical features have done so.
Ocean drilling offers the means for obtaining data that not only can test proposed
hypothetical links between climate and tectonics, but also can provide new data not easily
anticipated but relevant to understanding a number of processes in the earth. The present
proposal is for one leg in the Bay of Bengal, focused on its record of the erosional history of
the Himalaya and on the development of the Asian Monsoon over Cenozoic time. Because
geology lacks the tools for determining paleo-elevations except in unusual and ideal
circumstances, the sedimentary record of material eroded from a mountain belt holds the least
ambiguous record of its paleo-topography. Roughly 80% of the material eroded from the
Himalaya has been deposited in the Bay of Bengal, making it the most complete recorder. It
follows that without a more thorough investigation of the sediment deposited in that bay than
that provided by two legs, DSDP 22 and ODP 116, a knowledge of the interactions between
climate and the growth of the Himalaya and Tibet will, at best, be incomplete.
One more leg of drilling in the Bay of Bengal is likely to open more questions than it
answers, in large part because of lingering questions about how sediment will record both
topographic and climate changes in the region. For instance, the signature of the Asian
monsoon, if clear in parts of the Arabian Sea and the neighboring continents, is only
tentatively understood in the Bay of Bengal. Moreover, the deposition of sediment on a deep-
sea fan is not that of steady pelagic deposition commonly sought by paleoceanographers, but
comes in bursts along channels that spill onto levees. For sediment obtained in a single drill
hole to be interpretable, an understanding of such variations is needed. With the conviction
that one IODP leg in the Bay of Bengal cannot resolve all major problems that relate climate
and tectonics, we submit this project as one part of an integrated project of drilling in the
Himalayan basin. This includes multi-platform drilling in the Bay of Bengal for which we
also submit a pre-proposal this year to IODP as well as drilling in the Indus Fan for which a
proposal is submitted by another group. In this proposal, we focus on (1) the erosional history
of the Himalaya and its bearing on the development of the Himalaya and Tibet as topographic
552-full3 – Bengal Fan - Oct.
4
features, and (2) the development of the Asian monsoon in Cenozoic time as recorded in the
Bay of Bengal.
II - DRILLING OF BENGAL FAN: DISCUSSION OF OBJECTIVES
We seek a sedimentary record from the Bengal Fan to document the history of both the
Himalaya and the Asian monsoon for different periods. In this section we review the different
objectives and discuss how this project fits with another proposed Leg to drill the Indus Fan.
Figure 1 – Map of the Himalayan erosion system showing the positions of the proposed area
for drilling in the Bengal Fan: Middle Bengal Fan (MBF), and of the different DSDP and
ODP Sites documenting the Bengal and Indus fans or the monsoon history. Isopachs (in km)
of the Bengal Fan are simplified from (Curray, 1994). They represent the total sedimentary
and metasedimentary rocks above the oceanic second layer, as interpreted from seismic
reflection and refraction data.
MBF
30˚N
20˚N
10˚N
0˚
10˚S
60˚E 70˚E 80˚E 90˚E 100˚E
1 4
1 1
1
1
2
2
3
3
4
5
6
8 8
10
12
2
15
<1
<1
<1
Leg 116
218
217
216
758
Brahmaputra
215 211
222
720722
Tibet
H i m a l a y a
IndusFan
Indus
6
1821
2
2
Ganges
552-full3 – Bengal Fan - Oct.
5
CALIBRATION OF CHANGES AT 7-8 MA AND SINCE THAT TIME
Both tectonic and climate changes seem to have occurred at 7-8 Ma, and both are likely
to have written a signature in the Bay of Bengal (France-Lanord et al., 1993; Martinod and
Molnar, 1995). Moreover, there have been subsequent changes, both at ~2.5-3 Ma (Zhang et
al., 2001), when global cooling led to the growth of ice sheets in the Northern Hemisphere,
and at ~0.8-1 Ma, when the 100 ka cycle became strong and the rate and grain size of
sediment deposited increased in the Bengal fan. Both tectonic and climate changes have left
signatures in accumulation rates, grain sizes, clay mineralogy, isotopic ratios, organic carbon
burial, etc., that can be measured (Derry and France-Lanord, 1997; France-Lanord et al.,
1993).
Fig. 2 - Accumulation rate (Gartner, 1990), clay mineralogy (Bouquillon et al., 1990), Nd
isotopic data (Derry and France-Lanord, 1996; France-Lanord et al., 1993; Galy et al., 1996),
and total organic carbon isotopic composition (France-Lanord and Derry, 1994) from ODP
Leg 116 Holes 717C and 718C. Ages recalculated using time scale of Cande and Kent (Cande
and Kent, 1992). Low sedimentation rates (A), smectite-kaolinite (SK) clays (B) and organic
carbon derived from C4 plants (D) characterize the interval from 7.4 to 0.9 Ma. The Nd
isotopic composition (C) remain stable at all periods indicating the stability of the eroded
source of material. The biostratigraphic constraints on sediment accumulation are uncertain
for the early Miocene.
Accumulation
-20 -15 -10 -5
Nd
MicasVermiculite
< 2µm
Constant detrital sourceWeathering
0
2
4
6
8
10
12
14
16
18
200 200 400 600 800 0.3 0.6 0.90
Depth (mbsf) (Illite+Chlorite)/ Clays
+Smectite +Illite
-24 -21 -18 -15
13CTOC (‰)
C3 C4
C4 plants expansion
552-full3 – Bengal Fan - Oct.
6
First, to what extent are the variations in accumulation rates, clay mineralogy, and grain
sizes from Holes 717-719 (Fig. 2) representative of other parts of the fan? Because those
holes were drilled on the distal edge within a growing syncline, sediment transport might have
been affected both by the large distance from the source and by the barrier imposed by the
surrounding anticlines. Recall that the isotopic signature of the sediment allows its source
within the Himalaya to be identified. The decreases in accumulation rate and grain size at ~7
Ma and the synchronous increased percentage of smectite (Bouquillon et al., 1990) suggest
that if the monsoon strengthened at that time, it apparently did so without creating a more
energetic erosive system, as might be expected from the strong seasonal precipitation of the
monsoon. Obviously, if we find the same pattern of low accumulation rates, small grain
sizes, and a large percentage of smectite at 7-8 Ma in holes drilled at 8˚N (or 11˚N), we must
consider the possibility that if the monsoon strengthened at that time, it did so by decreasing,
not increasing erosion rates. If we find a sediment history different from that in holes 717-
719, we must conclude that the record on the distal edge of the fan does not record faithfully
the changes input at the source of the fan.
The present-day monsoon, if named originally for the seasonally steady winds over the
Arabian Sea, evokes the image of heavy rain over the Indian sub-continent. We have no
evidence to date, and perhaps conflicting evidence, showing that precipitation increased over
the Ganga and Brahmaputra drainage basins and the Bay of Bengal at 7-8 Ma (Derry and
France-Lanord, 1997; Dettman et al., 2001). Yet, because differences in δ18
O in planktonic
foraminifera deposited in the Bay of Bengal in late Quaternary time are related to amounts of
precipitation (Duplessy, 1982), and hence to the strength of the monsoon, we should have a
tool for detecting such changes earlier in Cenozoic time. Thus, we can assess the extent to
which the proxies for climate change in the Arabian Sea (such as increased G. Bulloides e.g.
(Kroon et al., 1991)) and on the Indian landmass (such as an increase in δ18
O (Quade et al.,
1995; Quade et al., 1989)) imply a strengthening of the monsoon as we understand it today.
Obviously, the absence of a change in δ18
O in planktonic foraminifera at 7-8 Ma would
cast doubt either on the idea that precipitation changed then, and hence that the monsoon as
we know it today strengthened at that time, or on the applicability of in δ18
O in planktonic
foraminifera to study of precipitation. Conversely, a demonstration that δ18
O in planktonic
foraminifera decreased at 7-8 Ma would suggest a change toward greater precipitation. Such
a result would, in turn, pose the question of why the response of sediment accumulation (and
erosion) to such a change at 7-8 Ma was opposite to what we expect for increased
precipitation.
The main reason for drilling more than one hole at 8˚N is to minimize the effect of
varying sedimentation rates associated with a pronounced increase in the vicinity of the active
channel at a time and its migration, and hence to avoid the biases that one hole (or a set of
adjacent holes) might give. Although the main focus of these holes is on the changes near 7-8
552-full3 – Bengal Fan - Oct.
7
Ma, obviously we will obtain material from a longer period. In one hole in the eastern Bay of
Bengal material older than 14 Ma shall be recovered, which will allow the kinds of studies
described above to test whether or not the monsoon strengthened during Early Miocene, as
proposed by Ramstein et al. (1997; Fluteau et al., 1999).
In addition, we plan to study other temporal, as well as spatial variations, in the
sediment over the last 7 Ma. Site 218 and those of Leg 116 show changes that possibly reveal
other variations in the erosion regime. Kroon et al. (1991) showed a dip in the abundance of
G. Bulloides at ~5 Ma, which might indicate a lull in the monsoon, the temporary dominance
of another upwelling-sensitive foraminifera (Kroon et al., 1991), or some other inadequacy of
Bulloides to measure the monsoon strength. We also seek quantitative measures of the
interaction between climate change and sedimentation associated with the global cooling and
onset of the Ice Age at 2.7-3 Ma and with the change from precession and obliquity-
dominated climate variations to the strong 100-ka cycle at 0.8-1 Ma. This latter change
appears to be marked in deposition rates, grain sizes, and clay mineralogy in ODP Holes 717-
719 (France-Lanord et al., 1993). Again, one objective is to decide how representative the
results from holes 717-719 are. The same proxies for monsoon strength and for erosion will
be available for study of this period. The results from holes 717-719 reveal no evidence of a
change in erosion rate at 2.7-3 Ma, in contrast with what might be expected if glacial erosion
were important and increased at that time. Moreover, if the only important change in
sedimentation rate, and hence presumably in erosion rate too, occurred at 0.8-1 Ma, such a
change would provide a clue to what kind of change was important. We anticipate being able
to resolve temporal variations on the time scale of orbital variations, but obviously we must
expect large variations in sedimentation rates. Hence, three holes on a transect are proposed
to limit the biases on long-term studies associated with penetrating buried channel-levee
systems, and another three holes shall be drilled in between to optimize the temporal sampling
of terrigenous sediment input and to analyze the impact of depocenter migration on
sedimentary facies and recorded signals.
The 7 Ma transition is also marked by the spectacular expansion of C4 photosynthetic
plants in the Himalayan basin (Quade et al., 1989). While C4 plant expansion may result from
a global decrease in atmospheric PCO2 (Cerling et al., 1997), recent studies suggest that PCO2
was already low at that period (Pagani et al., 1999). In the latter hypothesis, C4 plant
expansion would rather require a change to more arid conditions in the floodplain. Sediments
sampled at Leg 116 show close links among variations in clay mineralogy (smectite/illite
ratio), in total organic carbon, and in δ13
C (C3 vs. C4 plants) (France-Lanord and Derry, 1994;
Freeman and Colarusso, 2001). These relationships reveal changes in the sediment
provenance, with a mountain end-member delivering material unaltered with low organic
carbon content of C3 type and with a floodplain end-member delivering altered material with
high organic carbon content of C4 type. If confirmed by new drilling at the scale of the whole
552-full3 – Bengal Fan - Oct.
8
fan, such relations would favor the hypothesis of a regional climate change toward dryer
conditions.
SAMPLING OF THE OLDEST SEDIMENT OF THE FAN
Progress in dating the timing of the collision between India and the rest of Eurasia
provides a converging opinion that collision in the western Himalaya occurred between 50
and 55 Ma, but perhaps later (~45 Ma) in the eastern Himalaya, near Everest for instance
(Rowley, 1996; Rowley, 1998). When the Himalaya emerged as a mountain range, however,
remains less certain. Galy et al.(1996) showed, using differences between Rb/Sr cooling ages
(25-30 Ma) of biotite and stratigraphic ages (~18 Ma), that a deeply incised, and therefore
significant, mountain range existed at 30 Ma. Extending the record of sedimentation back in
time should allow a determination not only of when erosion began, but also of when erosion
had penetrated deep into the crust to expose rapidly cooled minerals. In particular, we should
be able to determine cooling ages of minerals whose closure temperatures are different, and
from the isotopic signature, we should be able to identify what rock of the Himalaya has
eroded. Then, the differences between cooling ages and stratigraphic ages will allow an
estimate not only of when erosion began, but also of when erosion had exhumed rock from
different depths (Copeland and Harrison, 1990; Corrigan and Crowley, 1990; Galy et al.,
1996).
Determining when emergence of the Himalaya took place might not provide any
surprises. Nevertheless, recall that all of the rock cropping out in the Himalaya was carried
by the Indian subcontinent and scraped off it following collision with Eurasia. Thus, given
the convergence rate of ~50 km/Myr, which India has moved north toward Eurasia since 45
Ma, if collision occurred at 45 Ma, but erosion began only at 35 Ma, we might infer that as
much as 500 km intact lithosphere was subducted beneath southern Eurasia before a
significant mountain range formed. Conversely, if deposition of rock with a Himalayan
isotopic fingerprint began shortly after 45 Ma, we must infer that some off-scraping of Indian
crust had occurred early in the history of the collision to build the initial Himalaya. Finally,
we can imagine a flux of sediment early in the history of the collision, but of Tibetan, not
Himalayan, origin. This would suggest some, if not necessarily easily quantified, subduction
of India beneath southern Tibet before thrust faulting within India created the Himalaya.
The well-known increase in the 87Sr/
86Sr ratio of sea water beginning at ~40 Ma
(DePaolo and Ingram, 1985; Hodell et al., 1989) is commonly attributed to increased erosion
and weathering in the Himalaya (Edmond, 1992; Galy et al., 1999; Krishnaswami et al., 1992;
Palmer and Edmond, 1989). A strong Himalayan signature, not only beginning at ~40 Ma,
but also contributing a pulse near 18 Ma (Richter et al., 1992), should, therefore, be
corroborated in the sedimentary record of Himalayan erosion. In particular, detrital silicates
552-full3 – Bengal Fan - Oct.
9
with high 87Sr/86Sr ratios both should increase at ~40 Ma and again near 18 Ma would
support such an attribution.. By extending the sedimentary record in the Bay of Bengal
before 20 Ma, we can examine the hypothesized correlation of the increased marine 87
Sr/86
Sr
ratio at 18 Ma with weathering of Himalayan rock rich in radiogenic strontium. If we can
sample the early history of Himalayan erosion, we can test the assumption that the increasing87
Sr/86
Sr ratio beginning at 40 Ma also results from weathering of Himalayan rock. The
sensitivity of the sea-water Sr isotopic budget to the Himalayan flux is so high (Galy et al.,
1999) that the sea-water evolution through time provides a unique system where erosion rate
can be estimated using a proxy other than accumulation rates. In particular, the Sr isotopic
composition of pedogenic clays sampled in the fan document the isotopic composition of the
rivers through time. As Derry and France-Lanord (1996) showed, this information combined
with the sea-water Sr isotopic budget should allow us to calculate the riverine flux of Sr. This
flux can be used as a proxy of the erosion flux.
The Bengal Fan is one of the thickest sediment sections in the world, and is far too thick
for sampling the very old section. The oldest part of the fan sampled to date was in the ODP
Leg 116 sites, where Early Miocene sediment (ca. 17 Ma) was sampled at Site 718 more than
2500 km from the present apex of the fan. Because of its southern position and the great water
depth, this site may not be adequate to penetrate “the oldest” sediment derived from the
Himalaya, because the fan may not have prograded so far south e.g. (Curray, 1994).
Therefore we propose a strategy for sampling a pre-Miocene section by drilling on the west
flank of the Ninetyeast Ridge, about 1300 km from the apex of the fan, where the section is
thinner, and where a possible Paleocene-Eocene unconformity (“P” horizon) could be reached
at a reasonable depth (Curray et al., 1982).
SPATIAL DEPOCENTER VARIABILITY
Sediment accumulates in the Bengal Fan largely by deposition in channel levee systems
(Fig. 3). On a cross section sampling below the active system, the fan appears to be built by
an accumulation of lenses corresponding to distinct channel-levee episodes intercalated by
slowly accumulated layers of fine grained sediment. Channels carry a flux of sediment for a
brief period, apparently of the order of some 1000 years, and then fill with sediment as a new
channel is cut into the levee system or outside it. Thus, accumulation at any point is very
irregular, varying from rates >30 m/kyr for periods as long as 3000 years (Hübscher et al.,
1997; Michels et al., 1998; Spiess et al., 1998; Weber et al., 1997), to very low accumulation
rates in intervening periods. Nd-Sr isotopic signatures demonstrate that sediment accumulated
at high rate is dominated by Himalayan material whereas low accumulation periods have
distinct isotopic signatures showing that other sources are mixed with Himalayan flux
(Pierson-Wickmann et al., 2001). Determining the distribution and typical lifetime of
552-full3 – Bengal Fan - Oct.
10
depocenters is vital for interpreting the older sedimentary record of the fan and to assign
different types of sedimentary facies and successions found in deep drill holes to structural
units. To address this objective, we propose to compare the upper 300 m of sediments across
the transect at an interval of appx. 50 km which is near the typical width of channel levee
systems at this latitude. This requires adding three shallow holes to the three deeper of the
transect.
Figure 3: Typical example of a buried channel-levee system from seismic line GeoB 97-027
at 8°N, shot with a 25 cu.in water gun with frequencies up to 1500 Hz. The width of the
structure is on the order of 30 km, the maximum height exceeds 50 meters.
FORCING OF THE CARBON CYCLE AND CLIMATE
Drilling the Bengal Fan should allow investigation of the global effect of the Himalayan
erosion on the Carbon cycle, which has been debated in the recent literature e.g. (France-
Lanord and Derry, 1997; Galy and France-Lanord, 1999; Godderis and Francois, 1995;
Goddéris and François, 1996; McCauley and De Paolo, 1997; Raymo, 1994; Raymo and
Ruddiman, 1992; Raymo et al., 1988; Ruddiman, 1997). Erosion tends to consume
atmospheric carbon by two mechanisms. First, atmospheric CO2 is consumed by the
weathering of silicates in soils to produce a fluvial alkalinity flux that later precipitates as
carbonate in sea-water. Second, plants debris and organic carbon adsorbed to clay minerals
are transported in the particulate flux and can be buried in deep-sea sediment. Both
mechanism will take up carbon from the atmosphere and store it over long term in the
sedimentary reservoir. Derry and France-Lanord (1997) suggested that the Himalayan erosion
consumes atmospheric CO2 via the burial of organic carbon preferentially to silicate
weathering. Nevertheless it remains impossible to assess the importance these processes at a
global scale because the past fluvial fluxes are unknown. The volume and the geochemistry
of sediment can provide direct and interpretable records of these fluxes, if their accumulation
rates in the Fan can be determined with sufficient accuracy. The proposed transect at 8°N
552-full3 – Bengal Fan - Oct.
11
will document a critical period when the accumulation rate decreased but silicate weathering
and organic carbon burial increases. These variations observed at Leg 116 Sites do not allow
us to establish a budget for the whole fan, but the proposed transect at 8°N will help us to
document variations on the regional scale. A record extending back before 20 Ma should also
allow study of potential impacts of the Himalaya on climate via both organic carbon burial
and silicate weathering.
COMPARISON OF THE BENGAL AND INDUS FANS
Reviewers and panel members will logically ask how drilling in the Bengal Fan relates
to drilling of the Indus Fan, proposed by Peter Clift and others, including two of us. First, we
do not intend to compete with that other proposal; we see them as complementary with each
offering solutions to relevant problems.
Drilling to the base of the Indus Fan, in order to study the early history of Himalayan
erosion, seems much easier than drilling the Bengal Fan, simply because the Indus Fan is
much the thinner. Yet, because current rates of sediment transport and total accumulations of
sediment in the Bengal Fan are roughly four times those of the Indus Fan, drilling of the
Bengal Fan might offer a more representative history of Himalayan erosion. Perhaps more
importantly, the isotopic record of sediment derived from the Himalaya and deposited in the
Bay of Bengal can be matched to that from different parts of the Himalaya, because of the
large range in isotopic compositions of source rock e.g. (Pierson-Wickmann et al., 2000).
This isotopic signature, however, is less clear in the drainage basin of the Indus River. For
instance, whereas the 87
Sr/86
Sr ratio of the Ganga River and its tributaries is notoriously high,
but that of the Indus is normal (Palmer and Edmond, 1989; Palmer and Edmond, 1992; Pande
et al., 1994). Thus, reconstructing the spatial history of erosion in the Himalaya should be
easier using the Bengal Fan than Indus Fan, for the period that we can sample in the Bay of
Bengal.
Second, the most convincing evidence of a 7-8-Ma development of the monsoon comes
from the Arabian Sea, near the Indus Fan, where the strength of the monsoon seems to be
reflected most clearly by proxies that measure upwelling of cold nutrient-rich water, which in
turn respond to the strength of the monsoonal winds. It follows that studying that variation
might be resolved better than in the Bay of Bengal, where the signature of the monsoon is
different and depends on changes in precipitation in the catchment of the Bay. Yet, because
the monsoon reveals its history differently, its study in the Bay of Bengal should enhance our
understanding of how the monsoon may have changed in time. Moreover, most of the rain
that falls during the monsoon flows into the Bay of Bengal, not the Arabian Sea, and most of
the sediment created by erosion associated with the monsoon, whose strength has varied with
time, will be deposited in the Bengal Fan. Thus, the record of the impact of changing
552-full3 – Bengal Fan - Oct.
12
monsoons on erosion will be clearer in the Bay of Bengal than in the Arabian Sea.
Thus, the sedimentary records in the Bengal and Indus Fans should differ from one
another and should record different aspects of the growth of the Himalaya and the
development of the Indian monsoon. They can be seen as sampling different part of the same
elephant and therefore necessary for a full understanding of the beast.
RELEVANCE TO THE INITIAL SCIENCE PLAN OF IODP
This proposal is clearly oriented toward the study of the interactions between climate
and tectonic identified as "Internal Forcing of Environmental Change" in the Initial Science
plan. The Himalayan erosion offers a rare place of the world where these interactions are
potentially so rich. They include geochemical effects on the carbon cycle via processes of
erosion, forcing of the climate by the orographic effect of the Himalaya and the thermal effect
of the Tibetan Plateau, and forcing of the tectonics by the action of the erosion.
More than one leg will be required to obtain the observations that relate the uplift and
the growth of the Himalaya and Tibet to Cenozoic climate in south Asia and the Indian
Ocean, necessary for understanding such interactions. A pre-proposal, is submitted in parallel,
to present a multi-platform approach of different objectives in the Bay of Bengal region (The
Himalaya - Bengal System: Studying links between Land and Ocean, Climate and Tectonics,
'Source' and 'Sink' by a multiplatform approach for drilling in the Bay of Bengal. by Spiess et
al.). The most important objective with respect to this proposal is the study of the active
channel-levee complexes which would document processes of sediment transport and fan
buildup and could turn up a wealth of information both illuminating how such systems evolve
and revealing a detailed climate record over short time scales.
Because the Bay of Bengal offers much to be learned (1) about the tectonics of the
Himalaya and Tibet, which cannot be learned from study of the rock exposed in those regions,
(2) about the Indian monsoon, and (3) about their interaction, as well as about sediment
transport on actively growing deep-sea fans, one leg cannot possibly solve all questions that
can be posed now. With that in mind, the leg proposed here is designed to address some
specific questions, but also to provide enough new material to design future legs more
narrowly focused on such questions.
III SUMMARY OF PROPOSED SITES AND DRILLING STRATEGY
High resolution multichannel seismic data, collected during Cruise SO 125 of R/V
Sonne in October/November 1997 (Spiess et al., 1998), with some published deep seismic
reflection data of Curray et al. ( 1982) and Gopala Rao et al. (1994; 1997), provide the basis
for selecting sites to drill. The new high resolution seismic data from R/V Sonne Cruise SO
552-full3 – Bengal Fan - Oct.
13
125 reveal fine scale structures within a fan invisible to conventional seismic methods.
Therefore we suggest to position all drill along the seismic lines GeoB 97-020/027, crossing
the Middle Bengal Fan at 8°N, using older data to define the regional structural framework.
The proposed drilling program is summarized in Table 1 based on specific assumptions
on penetration rates. We propose an east-west transect at 8°N of six drill sites which include
(Fig. 4 and 5) :
- one deep hole ~1500 m (MBF-3A) to reach pre-fan deposits
- two holes of ~900 m penetration (MBF-1A and 2A), to recover sediment at least as
old as 10-12 million years in order to study the Neogene fan evolution and the
impact of the monsoonal system on sediment supply and flux.
- in addition three more shallow holes of ~300 m penetration to achieve a complete
terrigenous record of the Himalayan flux over the last 1-2 million years.
Fig. 4 – Map showing the positions of drill sites MBF-1A to –6A on the 8°N transect and
seismic lines 97-20 to 27 and SIO M7-8.
The transect approach is necessary in order to account for lateral variability in the stacking
pattern of channel-levee structures through time. Because of the lateral migration of the active
channel, longer periods of low sediment accumulation or even non-deposition can occur
associated with major longitudinal shifts of depositional bands. To examine potential time
lags and numbers of channel-levee systems and to retrieve a more complete record in time,
90
E
89
E
88
E
87
E
86
E
85
E
7N
8N
9N
10N
9N
8N
7N
85
E
86
E
87
E
88
E
89
E
90
E
16
00
04
0812
16
20
00
04
08
12
16
20
22.1
0
00
04
08
12
16 20
23.10
00
04
08
12
16
20
24.1
0
00
04
08
12
16
20
25.1
0
00
040
8
12
26.1
0
16
20
00
27.1
0
12
16
20
00
04
08
12
16
01.0
301.0
3
DSDP 2
18=
MBF-1
A
MBF-4
A
MBF-5
A
MBF-2
A
MBF-6
A
MBF-3
A
DSDP 217
GeoB 97-020 GeoB 97-027
GC 22
T 10-11T 9 RS
IO M
6-7
SIO M7-8
GeoB 97-025
GeoB 97-023
Geo
B 9
7-02
2
-021
-026
-024
552-full3 – Bengal Fan - Oct.
14
the transect between the two ridges, which also restricts fan sedimentation to a 300 km wide
basin, seems to be best located at 8°N. At this latitude, sedimentation rate variations caused
by channel-levee systems are less pronounced than further North, and sediments are expected
to be sufficiently fine-grained to allow high quality drilling in the surface 300 meters. In
addition, DSDP Site 218 provides a sufficiently precise chronostratigraphic reference to
ensure the achievement of minimum drilling target ages of 10-14 Ma. This transect will
extend northward and back in time the existing record of Neogene fan sedimentation provided
by ODP Leg 116 sites and DSDP Site 218, allowing us to reconstruct a continuous record of
sediment accumulation across time intervals of major changes. The proposed holes lie
between the 85°E and 90°E ridges in a basin with relatively uniform sediment thickness for
each of the seismic units (Figs 4 and 5).
Table 1: Summary of proposed drilling in the Bay of Bengal including transit between sites.
Site /Latitude
Objective /Longitude Water depth Coring Techniques Penetration Drilling time days
Transit between sites 2.0
MBF-1A Neogene sedimentation history
8°0.42N 86°16.97E 3747 m APC/XCB 200/900 m 10.4
MBF-2A Neogene sedimentation history
8°0.4N 87°38'E 3678 m APC/XCB 200/900 m 10.4
MBF-3A Neogene history - Early fan history
8°0.4N 88°41'E 3620 m APC/XCB/RCB 200/900/1500 m 18.6
MBF-4A Depocenter migration
8°0.4N 86°47.9'E 3694 m APC/XCB 200/300 m 2.8
MBF-5A Depocenter migration
8°0.4N 87°10.9'E 3687 m APC/XCB 200/300 m 2.8
MBF-6A Depocenter migration
8°0.4N 88°6.6'E 3672 m APC/XCB 200/300 m 2.8
Total: 4200 m 49.8 days
Biostratigraphic information from DSDP Site 218 and recalculation of nannofossil ages
and zonations from the shipboard report (Von der Borch et al., 1974) provided an accurate
age specifically from the Discoaster hamatus (NN 9) zone with an age of 9.4-10.4 Ma in core
25, CC at 697 mbsf, which was used for seismic correlation between the proposed sites. The
seismic section (see Site Description Forms) as well as the line drawing of reflector segments
of R/V Sonne SO 125 seismic line GeoB 97-020/027 (Fig. 5) across the Bengal Fan at 8°N
shows the marker horizon of ~10 Ma age. To transfer drilling depth to two-way traveltime,
velocity information from multichannel data of Gopala Rao et al. (1997) was used, which
552-full3 – Bengal Fan - Oct.
15
provided for the upper 1 to 2 km interval velocity values of 1.7-1.8 km/s for Pleistocene, 1.9-
1.95 km/s for Pliocene/Pleistocene and 2.2-2.3 km/s for upper Miocene sediment though
having no age constraints on the seismic data. For our calculations a value of 1.9 km/s
average velocity was used for the upper 900 meters, an average of 2.1 km/s derived from
regional refraction data for the deep hole MBF-3A.
Figure 5: Line drawing of reflector segments of R/V Sonne SO 125 seismic line GeoB 97-
020/027 (See Map Fig. 4 and Figure in Site description Forms) across the Bengal Fan at 8°N
with positions of proposed drilling sites. Earlier seismic lines between 10 and 8° N are
figured for comparison. The marker horizon "M" of ~10 Ma age was correlated to DSDP
Site 218 (=MBF-1A). The deeper horizon "P" will be penetrated at Site MBF-3A. The general
depositional pattern indicates 50-80% higher sedimentation rates at site MBF-2A than at
DSDP Site 218 and 10-20% lower sedimentation rates at the easternmost site MBF-3A.
Drilling time was calculated for a water depth of appx. 3750 m for single APC coring to
200 m, and a change to XCB coring at rates of 30 m/hr from 200 to 500 mbsf and of 20 m/hr
from 500 to 900 mbsf. We expect to use only XCB technique to a sub-bottom depth of 900 m
T 10-11 M 6-7 M 7-8
GC-22W
DSDP218 M7-8
EDSDP 217
Reflector 'P'
P
M
P
M
EWSNWE T-9R GC-224
5
6
7
secs
4
5
6
7
secs
4
5
6
3
secs
50 km50 km50 km
4
5
6
3
secs
M
age ~10 Maage ~10 Ma
age ~10 Ma
Reflector 'P
'
Reflector 'P'
20 km
5.0
5.5
6.0
6.5
7.0
Two-
way
trav
eltim
e [s
]
500 ms
SIO M7-8
R/V Sonne SO125 Line GeoB 97-020/027 - Middle Bengal Fan (8°N)
MBF-2A
MBF-1A
DSDP Site
218
MBF-4A
MBF-6A
MBF-3A
MBF-5A
552-full3 – Bengal Fan - Oct.
16
based on the experience at ODP Site 718C, where similar fine-grained terrigenous sediment
had been drilled and XCB was used to 935 mbsf. Including 2-3 logging runs of 2 days
duration, total drilling time adds up to 10.4 days. Seismic data indicate that lithology likely
does not differ latitudinally, and calculations can therefore be applied to all sites. For the deep
hole MBF-3A, rotary coring is planned beneath 900 mbsf, adding appx. 7 days of drilling and
1 day of downhole logging. Additional sites MBF-4A to 6A are planned for 200 APC coring
and another 100 m XCB coring, adding a total of 2.8 days for each drill site.
For this revised version we evaluated all parameters relevant for drilling time, including
a recalculated biostratigraphic age for DSDP Site 218, which was used for seismic correlation
and for estimating a maximum penetration of 900 mbsf along the MBF transect. Using mostly
the higher values of penetration rates provided by ODP, based on previous experience from
ODP Leg 116, we estimate a total drilling time of 50 days. Uncertainties derive specifically
from the penetration rates at greater depth. We have assumed the sediment at 8°N to be of
similar composition and only moderate induration, as was found at ODP Site 718 and DSDP
Site 218.
The logging program is planned for two logging runs at each deeper site (MBF-1A to
3A) with the standard tool and the FMS/Acoustic tool. We think that this selection of tools,
which is of high-priority, is sufficient to reach the objectives of the proposal. Logging is
determinant to assess a continuous record of the relative proportion of clay and silt, the clay
mineralogy and the sedimentary structures. This is essential because the core recovery has
been problematic during Leg 116 when clay to silt alternation is rapid. In addition it will
document important problems of the fan hydrology that are not developed in this proposal.
For the evaluation of a more extended logging program we seek advice from the panels.
RELEVANCE OF PROPOSED SITES TO SCIENTIFIC OBJECTIVES
CALIBRATION OF CHANGES AT 7-8 MA AND SINCE THAT TIME - Three proposed sites (MBF-
1A to 3A) were positioned such it covers the width of the 300 km wide basin, between the 85
and the 90 East ridges. Site MBF-1A lies in the vicinity of DSDP Site 218. The seismic
structures appear to be relatively undisturbed. The latitude of 8°N allows reaching shallower
water depths than was possible at the equatorial sites of ODP Leg 116, where biostratigraphic
and paleomagnetic methods were difficult to apply. Farther north, however, sediment as old
as 10-12 Ma probably cannot be reached within a sub-bottom depth of 1000 m. Final location
selection might benefit from further processing of seismic data to identify buried channel-
levee systems in the sediment column and may be adjusted. The depositional patterns
indicate 50-80% higher sedimentation rates at site MBF-2A than at DSDP Site 218 and 10-
20% lower sedimentation rates at the easternmost site MBF-3A, which could allow to reach
an age of 14 Ma or older at a depth of 900 mbsf. Site MBF-2A will not reach the same age
within the depth range of 900-1000 mbsf.
MBF-2A MBF-6AMBF-4ADSDP 218
MBF-1A
MBF-3A
"P" refle
ctor
5.0
5.5
6.5
7.0
6.0
MBF-5A
Tw
o-w
ay tr
avel
time
(sec
)
552-full3 – Bengal Fan - Oct.
Figure 6: Seismic Line Geob 97/020/027 across the bengal Fan at 8°N. Proposed Site MBF-1A to 6A are indicated with their approximatepenetration assuming an average veolocity of 1900 m/s. Although reflector cannot be traced as isochrone across the fan, the basin character isclearly revealed between the 85°E Ridge and the Ninetyeast Ridge. A marker horizon was drawn, which could be corraelated to depth of ~700mbsf at DSDP Site 218 for an age of roughly 10 Ma. The penetration of DSDP Site 218 of 773 meters (spot coring; 251 m cored) is indicated bythe dotted bar.
17
552-full3 – Bengal Fan - Oct.
18
SAMPLING OF THE OLDEST SEDIMENT OF THE FAN - Two regional unconformities have been
identified and correlated throughout much of the Bengal Fan. The upper horizon, “M”, has
been shown both in DSDP 218 and in the ODP Leg 116 sites to be upper Miocene, about 7
my old. The onlap unconformity over much of the fan suggests that it correlates with a
deformation event that caused uplift over the hills and folds in the central and southern part of
the fan. The older unconformity, “P”, has been sampled only in the thin sediment section on
the Ninetyeast Ridge, DSDP sites 216 and 217, and in ODP site 358, and possibly in DSDP
sites 215 and 211 in the distal fan. It appears to be a hiatus of variable duration: from
Paleocene to Middle Eocene at DSDP 217, and from Paleocene to Pliocene in DSDP 211 in
the far distal fan. It has been postulated that the “P” horizon marks the onset of fan deposition
and progradation seaward, and that the section below the horizon is pre-fan pelagic or
hemipelagic sediment.
Seismic line GeoB 97-020/027 (Figs. 5 and 6) shows the “P” horizon at a depth of X
to Y sec TWT over the 8°N transect. For this objective, there is a competition between
drilling in the center of the transect where the progradation of the fan should be the oldest and
drilling thinner lateral site where “P” horizon can be reached at a shallower depth hence more
easily and with less diagenesis of the sediments. We selected Site MBF-3A where the “P “
horizon is at 1.2-1.3 sec to be reached above 1500 mbsf.
Velocities at greater depth were also estimated from correlation from refraction station
T-9R (Fig. 4 and 5), and a velocity of 2.12 km/s was derived from a compilation of refraction
data to “P” from 88 records from all over the fan, this converts to a depth of about 1190 m on
seismic line M7-8 and to a depth of 1150 m on line GeoB 97-020/027 near MBF-3A.
Extrapolating sediment accumulation rates from DSDP 218 and assuming a constant rate,
shows that the sediments overlying the “P” horizon would be of Lower Oligocene age. If the
rate of sediment accumulation were slower prior to 11 Ma, as shown in ODP site 718, the age
above the unconformity would be older.
SPATIAL DEPOCENTER VARIABILITY - We propose to drill three shallow holes (MBF-4A to -
6A) located between the three deeper holes of the 8°N transect. Together with MBF-1A to
3A, this would allow to compare in detail the migration of depocenter over the last one to two
million years. Six holes distributed over a transect of 200 km would allow a sufficient spatial
resolution on the basis of a typical width of channel levee system on the order of 50 km.
Penetration at the shallow holes should reach 300m in order to record the stacking of more
than two systems.
SITE SURVEYS
All of the proposed sites are at locations where seismic data are available. The transect
552-full3 – Bengal Fan - Oct.
19
at 8°N consists of one long line GeoB 97-020/027 (Fig. 3 and 4) and a grid in the vicinity of
DSDP Site 218 and proposed site MBF-1A. Crossing lines are not available for other
proposed sites, but additional data from Scripps Oceanographic Institution (Marianas 10, M7-
8) were used for the regional stratigraphic and structural framework.
SAFETY
Neither at Site 718 nor at Site 218 were safety and hydrocarbons an issue. We therefore
expect no problems with hydrocarbon or shallow gas. Although potential shallow gas should
exist in the fan sediment, so far there is no indication from seismic amplitudes at 8°N.
SUMMARY OF SEDIMENTOLOGICAL TRACERS TO BE USED
In the following, we list the principal sedimentological, mineralogical, and geochemical
tracers that will be used to interpret the sedimentary record. Most of them have already been
applied to the study of Bengal fan sediment, either over short time scales (Colin et al., 1996,
1998; Duplessy, 1982; Höhndorf et al., in press; Hübscher et al., 1997; Kudrass et al., 1998;
Pierson-Wickmann et al., 2001; Van Campo et al., 1982) or long ones (Bouquillon et al.,
1989; Bouquillon et al., 1990; Brass and Raman, 1990; Copeland et al., 1990; Derry and
France-Lanord, 1996; France-Lanord et al., 1993; France-Lanord and Derry, 1997; Galy et al.,
1996; Reisberg et al., 1996). Several of these tracers are sensitive to diagenesis or to the
condition of transport such as biogenic carbonates or organic matter.
Some of the interpretations of tracers that can be used in the Bengal fan are based on our
knowledge of the modern Himalaya. During the past few years, considerable efforts have
been made by groups in India, France, UK and USA, and our knowledge of the river system
and the effects of tectonic and climatic constraints on the erosion has improved considerably.
Such studies will be used to define the best tools to reconstruct the tectonic and climatic
history and the Himalayan basin.
CHRONOSTRATIGRAPHY: Dating sediments in formations such as the Bengal fan is a difficult
problem because of poor preservation of the biogenic carbonates. However, in the middle fan
sediments, nannofossil preservation is sufficient in Site 218 to allow dating at the million year
resolution. Magneto-stratigraphy will also be possible in the upper section of the sediments.
In addition, Ar-Ar ages on coarse muscovites and feldspars can be used to date exhumation of
the metamorphic rocks during erosion (Copeland et al., 1990) and should provide a maximum
age for sediments for Lower Miocene and Oligocene sediments.
ORIGIN OF DETRITAL MATERIAL: Determining the provenance of sediment is a major goal,
especially in the deep fan site as it documents the structural evolution of the Himalaya.
552-full3 – Bengal Fan - Oct.
20
- Coarse grain mineralogy
- H, O, Sr, Nd and Os isotopic composition of silicate material (whole rock, grain size
and mineral fractions). Nd isotopes is the most reliable tracers as it is not sensible to
diagenetic overprint which may be significant in a Hole as deep as 1.5 km. Single grain
analysis for Pb isotopes using ion probe also allow the identification of the specific sources
involved (Clift et al., in press).
- Magnetic properties. Recent studies by Colin et al. (1998) have shown on piston cores
of the Bay of Bengal the sensitivity of the tracer to source parameters.
- δ13
C of organic carbon applied on total organic carbon (France-Lanord and Derry,
1994) and on n-akanes (Freeman and Colarusso, 2001) allow to determine the origin (marine
vs. continental) of organic carbon and the type of vegetation (C3 vs.C4).
WEATHERING REGIME: By analogy to the modern Himalaya, the state of alteration of the
material accumulated in the fan depends on the rate of uplift and the intensity of precipitation.
It is therefore one of the indirect proxy for paleo-climatic conditions. It is documented by:
major element chemistry (Na/Al, Mg/Al, Ca/Al, etc.), clay mineralogy and isotopic
compositions (δ18O and δD), grain size distribution, accumulation rate, Sr isotopic
composition on pedogenic clays. Logging will be important to assess the relative proportion
of clay and silt when recovery is poor. Leg 116 had a relatively poor recovery in the 7 to 1
Myr. interval. It is likely that silt abundance has been underestimated in this interval because
of lower recovery of silty sediment with regard to mud.
EROSIONAL FLUXES: Accumulation rate is a direct function of the erosional flux. However,
contradictory results have been obtained for the Bengal fan depending on the sedimentary
records used (Burbank et al., 1993; Gartner, 1990; Métivier et al., 1999; Rea, 1992). We
contend that accumulation recorded in the lateral parts of the fan either on the Indian shelf or
the Ninety East ridge are not relevant for this problem. One main result of this proposal
should be to test the regional representativeness of deposition variations. Also, Sr isotopic
composition of pedogenic minerals, document past riverine fluxes of Sr (Derry and France-
Lanord, 1996), which can be further related to the general erosion of the range.
RATE OF EROSION AND TRANSPORT AND UPLIFT HISTORY:
- Erosional fluxes
- Geochronology, Ar-Ar dating on feldspars and micas, Rb-Sr on biotite have been used
on sediments of Leg 116 to document the rate of exhumation (Copeland et al., 1990; Galy et
al., 1996). New methods with low closure temperatures as U-He on apatite or cosmogenic
isotopes will be important complement. Cosmogenic isotopes 10
Be on quartz for sediments
less than 2 Ma and He on garnet allow indirect estimates of transport rate in the modern river
system.
MONSOON-CLIMATE AND PALEOVEGETATION: The only known direct tracer of the monsoon
intensity in the Bay of Bengal is δ18O of planktonic foraminifers. This has been determined
552-full3 – Bengal Fan - Oct.
21
on Holocene to late Pleistocene piston cores of the proximal fan but it has never been applied
to Neogene samples e.g.(Duplessy, 1982). In principle this could be possible in the middle fan
sites.
The combination of the variation of the weathering regime, paleo-vegetation determined
from the palynological and carbon isotopic studies, and erosional fluxes provides an indirect
indication of monsoon strength, based on our knowledge of both the modern erosion system
(Galy and France-Lanord, 1999; Galy and France-Lanord, 2001; Goodbred and Kuehl, 2001;
Singh and France-Lanord, 2001) and the continental record of the Siwaliks (Dettman et al.,
2001; Hoorn et al., 2000).
REFERENCES
Bouquillon A., Chamley H., and Fröhlich F. (1989) Sédimentation argileuse au Cénozoïque
supérieur dans l'océan Indien Nord-oriental. Oceanologica Acta 12, 133-147.
Bouquillon A., France-Lanord C., Michard A., and Tiercelin J.-J. (1990) Sedimentology and
isotopic chemistry of the Bengal fan sediments: the denudation of the Himalaya. In Proc.
ODP, Sci. Res., Vol. 116 (ed. J. R. Cochran, D. A. V. Stow, and et al.), pp. 43-58.
Brass G. W. and Raman C. V. (1990) Clay mineralogy of sediments from the Bengal fan. In
Proc. ODP, Sci. Res., Vol. 116 (ed. J. R. Cochran and D. A. V. Stow), pp. 35-41.
Burbank D. W., Derry L. A., and France-Lanord C. (1993) Reduced Himalayan sediment
production 8 Myr ago despite an intensified monsoon. Nature 364, 48-50.
Cande S. C. and Kent D. (1992) A new geomagnetic polarity time scale for the late
Cretaceous and Cenozoic. Journal of Geophysical Research 97(B10), 13917-13951.
Cerling T. E., Harris J. M., MacFadden B. J., Leakey M. G., Quade J., Eisenmann V., and
Ehrleringer J. R. (1997) Global vegetation change through the Miocene/Pliocene boundary,
. Nature 389, 153-158.
Clift P. D., Shimizu N., Layne G., Gaedicke C., Schlüter H. U., Clark M., and Amjad S. (in
press) Development of the Indus fan and its significance for the erosion history of the
western Himalaya and Karakoram. Geological Society of America Bulletin.
Colin C., Kissel C., Blamart D., and Turpin L. (1998) Magnetic properties of sediments in the
Bay of Bengal and the Andaman Sea: impact of rapid North Atlantic Ocean climatic events
on the strength of the Indian monsoon,. Earth and Planetary Science Letters 160, 623-635.
Colin C., Turpin L., Kissel C., Desprairies A., and Bertaux J. (1996) Climate-Related
Changes in the Himalaya Area. Annales Geophysicae 14, 580.
Copeland P. and Harrison T. M. (1990) Episodic rapid uplift in the Himalaya revealed by40
Ar/39
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detrital muscovite and K-feldspar from ODP Leg 116, southern Bengal Fan : Implications
552-full3 – Bengal Fan - Oct.
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for the uplift and erosion of the Himalaya. In Proc. ODP, Sci. Res., Vol. 116 (ed. J. R.
Cochran, Stow, D.A.V. et al.), pp. 93-114.
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geological history of the northeastern Indian ocean. In Ocean basin and margins, Vol. 6
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Derry L. A. and France-Lanord C. (1996) Neogene Himalayan weathering history and river87Sr/86Sr: Impact on the marine Sr record. Earth and Planetary Science Letters 142, 59-
74.
Derry L. A. and France-Lanord C. (1997) Himalayan weathering and erosion fluxes: climate
and tectonic controls. In Tectonic uplift and climate change (ed. W. F. Ruddiman), pp.
289-312. Plenum.
Dettman D., Kohn M., Quade J., Ryerson F., Ojha T., and Hamidullah S. (2001) Seasonal
stable isotope evidence for a strong Asian monsoon throughout the past10.7 m.y. Geology
29, 31-34.
Duplessy J. C. (1982) Glacial to interglacial contrasts in the northern Indian Ocean, . Nature
295, 494-498.
Edmond J. M. (1992) Himalayan tectonics, weathering processes, and the strontium isotope
record in marine limestones. Science 258, 1594-1597.
Fluteau F., Ramstein G., and Besse J. (1999) Simulating the evolution of the Asian and
African monsoons during the past 30 million years using an atmospheric general
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France-Lanord C., Derry L., and Michard A. (1993) Evolution of the Himalaya since Miocene
time: isotopic and sedimentologic evidence from the Bengal Fan. In Himalayan Tectonics,
Vol. 74 (ed. P. J. Treloar and M. Searle), pp. 603-621. Geol. Soc. Lond.
France-Lanord C. and Derry L. A. (1994) δ13
C of organic carbon in the Bengal fan: source
evolution and transport of C3 and C4 plant carbon to marine sediments. Geochimica et
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France-Lanord C. and Derry L. A. (1997) Organic carbon burial forcing of the carbon cycle
from Himalayan erosion. Nature 390, 65-67.
Freeman K. H. and Colarusso L. A. (2001) Molecular and isotopic records of C4 grassland
expansion in the late Miocene. Geochimica et Cosmochimica Acta 65, 1439-1454.
552-full3 – Bengal Fan - Oct.
23
Galy A. and France-Lanord C. (1999) Processes of the Weathering in the Ganges-
Brahmaputra basin and the riverine alkalinity budget. Chemical Geology 159, 31-60.
Galy A. and France-Lanord C. (2001) Higher Erosion rates in the Himalaya: geochemical
constraints on riverine fluxes. Geology 29, 23-26.
Galy A., France-Lanord C., and Derry L. A. (1996) Oligo-Miocene uplift and unroofing of the
Himalaya: evidence from the Bengal Fan. Tectonophysics 260, 109-118.
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Himalayan Rivers in Nepal and Bangladesh. Geochimica et Cosmochimica Acta 63, 1905-
1925.
Gartner S. (1990) Neogene calcareous nannofossil biostratigraphy, Leg 116 (Central Indian
Ocean). In Proc. ODP, Sci. Res., Vol. 116 (ed. J. R. Cochran, D. A. V. Stow, and et al.),
pp. 165-187. Ocean Drilling Program.
Godderis Y. and Francois L. M. (1995) The Cenozoic evolution of the strontium and carbon
cycles: Relative importance of continental erosion and mantle exchanges. Chemical
Geology 126(2), 169-190.
Goddéris Y. and François L. M. (1996) Balancing the Cenozoic carbon and alkalinity cycles:
Constraints from isotopic records. Geophysical Research Letters 23, 3743-3746.
Goodbred S. L. and Kuehl S. A. (2001) Enormous Ganges-Brahmaputra sediment discharge
during strengthened early Holocene monsoon. Geology 28(12), 1083-1086.
Gopala Rao D., Bhattacharya G., Ramana M., Subhramanyam V., Ramprasad T., Krishna K.,
Chubey A., Murty G., Srinivas K., and Desa M. (1994) Analysis of Multi-Channel Seismic
Reflection and Magnetic Data Along 13°N Latitude Across the Bay of Bengal,. Marine
Geophysical Researches 16, 225-236.
Gopala Rao D., Krishna K., and Sar D. (1997) Crustal evolution and sedimentation history of
the Bay of Bengal since the Cretaceous,. Journal of Geophysical Research 102, 17747-
17768.
Hodell D. A., Mueller P. A., McKenzie J. A., and Mead G. A. (1989) Strontium isotope
stratigraphy and geochemistry of the late Neogene ocean. Earth and Planetary Science
Letters 92, 165-178.
Höhndorf A., Kudrass H. R., and France-Lanord C. (in press) Transfer of the Sr isotopic
signature of the Himalayas to the Bay of Bengal. Deep-sea research part a-oceanographic
research papers.
Hoorn C., Ohja T., and Quade J. (2000) Palynological evidence for vegetation devlopment
and climatic change in the Sub-Himalayan Zone (Neogene, Central Nepal).
Paleogeography, Paleoclimatology, Paleoecology 163, 133-161.
Hübscher C., Spiess V., Breitzke M., and Weber M. E. (1997) The youngest channel-levee
system of the Bengal Fan : results from digitalsediment echosounder data. Marine Geology
141, 125-145.
552-full3 – Bengal Fan - Oct.
24
Krishnaswami S., Trivedi J. R., Sarin M. M., Ramesh R., and Sharma K. K. (1992) Strontium
isotopes and rubidium in the Ganga-Brahmaputra river system: Weathering in the
Himalaya, fluxes to the Bay of Bengal and contributions to the evolution of oceanic87Sr/86Sr. Earth and Planetary Science Letters 109, 243-253.
Kroon D., Steens T., and Troelstra S. R. (1991) Onset of monsoonal related upwelling in the
western Arabian Sea as revealed by planktonic foraminifers. In Proc. ODP, Sci. Res., Vol.
117 (ed. W. L. Prell, N. Niitsuma, and e. al.), pp. 257-263.
Kudrass H. R., Michels K., Wiedicke M., and Suckow A. (1998) Cyclones and tides as
feeders of a submarine canyon off Bangladesh, . Geology 26, 715-718.
Martinod J. and Molnar P. (1995) Lithospheric folding in the Indian Ocean and the rheology
of the oceanic plate,. Bulletin de la Société géologique de France 166, 813-821.
McCauley S. E. and De Paolo D. J. (1997) The marine 87Sr/86Sr and δ18O
records, Himalayan Alkalinity fluxes, and Cenozoic climate Models. In Uplift and Climate
Change (ed. W. F. Ruddiman), pp. 289-312. Plenum Press.
Métivier F., Gaudemer Y., Tapponier P., and Klein M. (1999) Mass accumulation rates in
Asia during the Cenozoic, . Geophysical Journal International 137, 280-318.
Michels K., Kudrass H., Hübscher C., Suckow A., and Wiedicke M. (1998) The submarine
delta of the Ganges-Brahmaputra: cyclone-dominated sedimentation patterns,. Marine
Geology 149, 133-154.
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concentrations and the expansion of C4 grasses. Science 285, 876-879.
Palmer M. R. and Edmond J. M. (1989) The strontium isotope budget of the modern ocean.
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Palmer M. R. and Edmond J. M. (1992) Controls over the strontium isotope composition of
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552-full3 – Bengal Fan - Oct.
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5
iSAS/IODP Site Summary Forms:Form 1 - General Site Information(Submitted with Preliminary Proposal)
Please fill out information in all gray boxes ___New RevisedSection A: Proposal Information
Title of Proposal: Neogene and late Paleogene record of Himalayan orogeny and climate: a transect
across the Middle Bengal Fan.
Date Form
Submitted:1 October 2001
Site Specific
Objectives with
Priority(Must include
general objectives in
proposal)
Neogene sedimentation history,
Depocenter migration
List Previous
Drilling in Area:DSDP Legs 21, 22, ODP Leg 116
Section B: General Site InformationSite Name:
(e.g. SWPAC-01A)MBF-1A If site is a reoccupation
of an old DSDP/ODP
Site, Please include
former Site #218
Area or Location: Middle Bengal Fan
Latitude:Deg: 8 N Min: 0.42N
Jurisdiction: International/India
Longitude:Deg: 86 E Min: 16.97E
Distance to Land:
Coordinates
System:__WGS 84, _Other ( )
Priority of Site: Primary: X Alt: Water Depth: 3747 m
6
Section C: Operational Information
Sediments Basement
900 mProposed
Penetration:
(m) What is the total sed. thickness? ? > 2000 m
no
Total Penetration: 900 m
General
Lithologies:Mud turbidites
1-APX/XCBCoring Plan:(Specify or Circle)
1-APC VPC* XCB MDCB* PCS RCB Re-entry HRGB
Standard Tools Special Tools LWDNeutron-Porosity Borehole Televiewer Formation Fluid Sampling Density-Neutron
Litho-DensityNuclear Magnetic
Resonance
Borehole Temperature &
PressureResistivity-Gamma Ray
Gamma Ray Geochemical Borehole Seismic Acoustic
Resistivity Side-Wall Core Sampling
Acoustic
Wireline
Logging Plan:
Formation Image Others ( ) Others ( )
Max.Borehole
Temp. :
Expected value (For Riser Drilling)
Cuttings Sampling Intervals
from m to m, m intervals
from m to m, m intervals
Mud Logging:
(Riser Holes Only)
Basic Sampling Intervals: 5m
Estimated days: Drilling/Coring:8.4 Logging:2 Total On-Site:10.4
Future Plan: Longterm Borehole Observation Plan/Re-entry Plan
Please check flowing List of Potential Hazards
Shallow GasComplicated GeologicalStructures
Hydrothermal Activity
What is your Weather window?
(Preferable period with the
reasons)
Hydrocarbon Soft Seabed Landslide and Turbidity Current
Shallow Water Flow Irregular Seabed Methane Hydrate
Abnormal Pressure Currents Diapir and Mud Volcano
Man-made Objects Fractured Zone High Temperature
H2S Fault Ice Conditions
Hazards/
Weather:
CO2 High Dip Angle
°C
7
New RevisedPlease fill out information in all gray boxes
Proposal #: 552-full3 Site #: MBF-1A Date Form Submitted: Oct. 2001
Data Type
SSPRequir-ements
ExistsIn DB Details of available data and data that are still to be collected
1High resolutionseismic reflection
Primary Line(s): Location of Site on line (SP or Time only)R/V Sonne Cruise SO 125 Multichannel, 48 ch, GeoB 97-020/027, GI Gun 0.4 l, Watergun 0.16 l,trace# 2900Crossing Lines(s): no
2Deep Penetrationseismic reflection
Primary Line(s): Pre-Site survey data of ODP Leg 116 Location of Site on line (SP or Time only)R/V Sonne Cruise SO 125 Multichannel, 48 chGeoB 97-020/027, seismic signal penetration >2 strace# 2900Crossing Lines(s):
3 Seismic Velocity† SO 125 velocity information (750 m Offset) not yet available,velocity model from Gopala Rao et al. (1997)
4 Seismic Grid no
5a Refraction(surface)
no
5b Refraction(near bottom)
Yes 10°N 88.5°E T9R (J. Curray, Scripps)
6 3.5 kHz yes, digital Parasound Location of Site on line(Time)
7 Swathbathymetry
yes, Hydrosweep
8a Side-lookingsonar (surface)
yes, Hydrosweep scatter amplitudes, 59 beams
8b Side-lookingsonar (bottom)
9 Photographyor Video
10 Heat Flow
11a Magnetics
11b Gravity
12 Sediment cores13 Rock sampling
14a Water current data14b Ice Conditions15 OBS
microseismicity16 Navigation
17 Other
SSP Classification of Site: SSP Watchdog: Date of Last Review:SSP Comments:
X=required; X*=may be required for specific sites; Y=recommended; Y*=may be recommended for specific sites; R=required forre-entry sites; T=required for high temperature environments; † Accurate velocity information is required for holes deeper than400m.
iSAS/IODP Site Summary Forms: Form 2 - Site Survey Detail
8
New Revised
Proposal #: 552-full3 Site #: MBF-1A Date Form Submitted: Oct 2001Water Depth (m): 3747 m Sed. Penetration (m): 900 m Basement Penetration (m): no
Do you need to use the conical side-entry sub (CSES) at this site? Yes No
Are high temperatures expected at this site? Yes No
Are there any other special requirements for logging at this site? Yes No
If “Yes” Please describe requirements:
What do you estimate the total logging time for this site to be:
Measurement Type Scientific ObjectiveRelevance
(1=high, 3=Low)
Neutron-Porosity Yes -Fan hydrology 2
Litho-Density Yes - Silt/Clay ratio, clay mineralogy 1
Natural Gamma Ray Yes - Silt/Clay ratio, clay mineralogy 1
Resistivity-Induction Fan hydrology 2
Acoustic Yes - Calibration of seismic velocity
Fan hydrology
1
2
FMS Yes - Sedimentary structure and facies 1
BHTV No
Resistivity-Laterolog No
Magnetic/Susceptibility Yes - Silt/Clay ratio, clay mineralogy 2
Density-Neutron (LWD) No
Resitivity-Gamma Ray
(LWD)
no
Other: Special tools (CORK,
PACKER, VSP, PCS, FWS,
WSP
no
For help in determining logging times, please contact the ODP-LDEO Wireline Logging Services groupat:
[email protected]://www.ldeo.columbia.edu/BRG/brg_home.htmlPhone/Fax: (914) 365-8674 / (914) 365-3182
Note: Sites with greater than 400 m ofpenetration or significant basementpenetration require deployment ofstandard toolstrings.
iSAS/IODP Site Summary Forms: Form 3 - Detailed Logging Plan
9
New RevisedPlease fill out information in all gray boxes
Proposal #: 552-full3 Site #: MBF-1A Date Form Submitted: 1 october 2001
1 Summary of Operations at site:(Example: Triple-APC to refusal, XCB10 m into basement, log as shown onpage 3.)
Single APC to refusal (~200 m)XCB down to 900 mbsf
2 Based on Previous DSDP/ODPdrilling, list all hydrocarbonoccurrences of greater thanbackground levels. Give natureof show, age and depth of rock:
no
3 From Available information,list all commercial drilling inthis area that produced oryielded significant hydrocarbonshows. Give depths and ages ofhydrocarbon-bearing deposits.
no
4 Are there any indications of gashydrates at this location?
no
5 Are there reasons to expecthydrocarbon accumulations atthis site? Please give details.
no
6 What “special” precautions willbe taken during drilling?
no
7 What abandonment proceduresdo you plan to follow:
no
8 Please list other natural ormanmade hazards which mayeffect ship’s operations:(e.g. ice, currents, cables)
no
9 Summary: What do youconsider the major risks indrilling at this site?
no
iSAS/IODP Site Summary Forms: Form 4 – Pollution & Safety Hazard Summary
New RevisedProposal # 552-Full3 Site #: MBF-1A Date Form Submitted: October 2001
Sub-bottom
depth (m)
Key reflectors,Unconformities,
faults, etcAge
Assumedvelocity(km/sec)
Lithology Paleo-environmentAve. rate of
sedimentaccumulation
(m/My)
Comments
0-700700
700-900
"M" reflector
0-10Ma10 Ma ?>10 Ma
1.9
1.9
Mud turbidites
Mud turbidites
Deep sea fan
Deep sea fan
70
70
iSAS/IODP Site Summary Forms: Form 5 - Lithologic Summary
10
11
iSAS/IODP Site Summary Forms:Form 1 - General Site Information(Submitted with Preliminary Proposal)
Please fill out information in all gray boxes ___New RevisedSection A: Proposal Information
Title of Proposal: Neogene and late Paleogene record of Himalayan orogeny and climate: a transect
across the Middle Bengal Fan.
Date Form
Submitted:1 October 2001
Site Specific
Objectives with
Priority(Must include
general objectives in
proposal)
Neogene sedimentation history,
Depocenter migration
List Previous
Drilling in Area:DSDP Legs 21, 22, ODP Leg 116
Section B: General Site InformationSite Name:
(e.g. SWPAC-01A)MBF-2A If site is a reoccupation
of an old DSDP/ODP
Site, Please include
Area or Location: Middle Bengal Fan
Latitude:Deg: 8 N Min: 0.4N
Jurisdiction: International/India
Longitude:Deg: 87 E Min: 38E
Distance to Land:
Coordinates
System:__WGS 84, _Other ( )
Priority of Site: Primary: X Alt: Water Depth: 3678 m
12
Section C: Operational Information
Sediments Basement
900 mProposed
Penetration:
(m) What is the total sed. thickness? ? > 2000 m
no
Total Penetration: 900 m
General
Lithologies:Mud turbidites
1-APX/XCBCoring Plan:(Specify or Circle)
1-APC VPC* XCB MDCB* PCS RCB Re-entry HRGB
Standard Tools Special Tools LWDNeutron-Porosity Borehole Televiewer Formation Fluid Sampling Density-Neutron
Litho-DensityNuclear Magnetic
Resonance
Borehole Temperature &
PressureResistivity-Gamma Ray
Gamma Ray Geochemical Borehole Seismic Acoustic
Resistivity Side-Wall Core Sampling
Acoustic
Wireline
Logging Plan:
Formation Image Others ( ) Others ( )
Max.Borehole
Temp. :
Expected value (For Riser Drilling)
Cuttings Sampling Intervals
from m to m, m intervals
from m to m, m intervals
Mud Logging:
(Riser Holes Only)
Basic Sampling Intervals: 5m
Estimated days: Drilling/Coring:8.4 Logging:2 Total On-Site:10.4
Future Plan: Longterm Borehole Observation Plan/Re-entry Plan
Please check flowing List of Potential Hazards
Shallow GasComplicated GeologicalStructures
Hydrothermal Activity
What is your Weather window?
(Preferable period with the
reasons)
Hydrocarbon Soft Seabed Landslide and Turbidity Current
Shallow Water Flow Irregular Seabed Methane Hydrate
Abnormal Pressure Currents Diapir and Mud Volcano
Man-made Objects Fractured Zone High Temperature
H2S Fault Ice Conditions
Hazards/
Weather:
CO2 High Dip Angle
°C
13
New RevisedPlease fill out information in all gray boxes
Proposal #: 552-full3 Site #: MBF-2A Date Form Submitted: Oct. 2001
Data Type
SSPRequir-ements
ExistsIn DB Details of available data and data that are still to be collected
1High resolutionseismic reflection
Primary Line(s): Location of Site on line (SP or Time only)R/V Sonne Cruise SO 125 Multichannel, 48 ch, GeoB 97-020/027, GI Gun 0.4 l, Watergun 0.16 l,trace# 2900Crossing Lines(s): no
2Deep Penetrationseismic reflection
Primary Line(s): Pre-Site survey data of ODP Leg 116 Location of Site on line (SP or Time only)R/V Sonne Cruise SO 125 Multichannel, 48 chGeoB 97-020/027, seismic signal penetration >2 strace# 2900Crossing Lines(s):
3 Seismic Velocity† SO 125 velocity information (750 m Offset) not yet available,velocity model from Gopala Rao et al. (1997)
4 Seismic Grid no
5a Refraction(surface)
no
5b Refraction(near bottom)
Yes 10°N 88.5°E T9R (J. Curray, Scripps)
6 3.5 kHz yes, digital Parasound Location of Site on line(Time)
7 Swathbathymetry
yes, Hydrosweep
8a Side-lookingsonar (surface)
yes, Hydrosweep scatter amplitudes, 59 beams
8b Side-lookingsonar (bottom)
9 Photographyor Video
10 Heat Flow
11a Magnetics
11b Gravity
12 Sediment cores13 Rock sampling
14a Water current data14b Ice Conditions15 OBS
microseismicity16 Navigation
17 Other
SSP Classification of Site: SSP Watchdog: Date of Last Review:SSP Comments:
X=required; X*=may be required for specific sites; Y=recommended; Y*=may be recommended for specific sites; R=required forre-entry sites; T=required for high temperature environments; † Accurate velocity information is required for holes deeper than400m.
iSAS/IODP Site Summary Forms: Form 2 - Site Survey Detail
14
New Revised
Proposal #: 552-full3 Site #: MBF-2A Date Form Submitted: Oct 2001Water Depth (m): 3678 m Sed. Penetration (m): 900 m Basement Penetration (m): no
Do you need to use the conical side-entry sub (CSES) at this site? Yes No
Are high temperatures expected at this site? Yes No
Are there any other special requirements for logging at this site? Yes No
If “Yes” Please describe requirements:
What do you estimate the total logging time for this site to be:
Measurement Type Scientific ObjectiveRelevance
(1=high, 3=Low)
Neutron-Porosity Yes -Fan hydrology 2
Litho-Density Yes - Silt/Clay ratio, clay mineralogy 1
Natural Gamma Ray Yes - Silt/Clay ratio, clay mineralogy 1
Resistivity-Induction Fan hydrology 2
Acoustic Yes - Calibration of seismic velocity
Fan hydrology
1
2
FMS Yes - Sedimentary structure and facies 1
BHTV No
Resistivity-Laterolog No
Magnetic/Susceptibility Yes - Silt/Clay ratio, clay mineralogy 2
Density-Neutron (LWD) No
Resitivity-Gamma Ray
(LWD)
no
Other: Special tools (CORK,
PACKER, VSP, PCS, FWS,
WSP
no
For help in determining logging times, please contact the ODP-LDEO Wireline Logging Services groupat:
[email protected]://www.ldeo.columbia.edu/BRG/brg_home.htmlPhone/Fax: (914) 365-8674 / (914) 365-3182
Note: Sites with greater than 400 m ofpenetration or significant basementpenetration require deployment ofstandard toolstrings.
iSAS/IODP Site Summary Forms: Form 3 - Detailed Logging Plan
15
New RevisedPlease fill out information in all gray boxes
Proposal #: 552-full3 Site #: MBF-2A Date Form Submitted: october 2001
1 Summary of Operations at site:(Example: Triple-APC to refusal, XCB10 m into basement, log as shown onpage 3.)
Single APC to refusal (~200 m)XCB down to 900 mbsf
2 Based on Previous DSDP/ODPdrilling, list all hydrocarbonoccurrences of greater thanbackground levels. Give natureof show, age and depth of rock:
no
3 From Available information,list all commercial drilling inthis area that produced oryielded significant hydrocarbonshows. Give depths and ages ofhydrocarbon-bearing deposits.
no
4 Are there any indications of gashydrates at this location?
no
5 Are there reasons to expecthydrocarbon accumulations atthis site? Please give details.
no
6 What “special” precautions willbe taken during drilling?
no
7 What abandonment proceduresdo you plan to follow:
no
8 Please list other natural ormanmade hazards which mayeffect ship’s operations:(e.g. ice, currents, cables)
no
9 Summary: What do youconsider the major risks indrilling at this site?
no
iSAS/IODP Site Summary Forms: Form 4 – Pollution & Safety Hazard Summary
New RevisedProposal # 552-Full3 Site #: MBF-2A Date Form Submitted: October 2001
Sub-bottom
depth (m)
Key reflectors,Unconformities,
faults, etcAge
Assumedvelocity(km/sec)
Lithology Paleo-environmentAve. rate of
sedimentaccumulation
(m/My)
Comments
0-900
1150
"
M" reflector
0-<10Ma
10 Ma ?
1.9 Mud turbidites Deep sea fan 110
iSAS/IODP Site Summary Forms: Form 5 - Lithologic Summary
16
17
iSAS/IODP Site Summary Forms:Form 1 - General Site Information(Submitted with Preliminary Proposal)
Please fill out information in all gray boxes ___New RevisedSection A: Proposal Information
Title of Proposal: Neogene and late Paleogene record of Himalayan orogeny and climate: a transect
across the Middle Bengal Fan.
Date Form
Submitted:1 October 2001
Site Specific
Objectives with
Priority(Must include
general objectives in
proposal)
Neogene and pre-Neogene sedimentation history,
Depocenter migration
List Previous
Drilling in Area:DSDP Legs 21, 22, ODP Leg 116
Section B: General Site InformationSite Name:
(e.g. SWPAC-01A)MBF-3A If site is a reoccupation
of an old DSDP/ODP
Site, Please include
former Site #
Area or Location: Middle Bengal Fan
Latitude:Deg: 8 N Min: 0.4N
Jurisdiction: International/India
Longitude:Deg: 88 E Min: 41E
Distance to Land:
Coordinates
System:__WGS 84, _Other ( )
Priority of Site: Primary: X Alt: Water Depth: 3620 m
18
Section C: Operational Information
Sediments Basement
1500 mProposed
Penetration:
(m) What is the total sed. thickness? ? > 2000 m
no
Total Penetration: 1500 m
General
Lithologies:Mud turbidites
1-APC / XCB / RCBCoring Plan:(Specify or Circle)
1-APC VPC* XCB MDCB* PCS RCB Re-entry HRGB
Standard Tools Special Tools LWDNeutron-Porosity Borehole Televiewer Formation Fluid Sampling Density-Neutron
Litho-DensityNuclear Magnetic
Resonance
Borehole Temperature &
PressureResistivity-Gamma Ray
Gamma Ray Geochemical Borehole Seismic Acoustic
Resistivity Side-Wall Core Sampling
Acoustic
Wireline
Logging Plan:
Formation Image Others ( ) Others ( )
Max.Borehole
Temp. :
Expected value (For Riser Drilling)
Cuttings Sampling Intervals
from m to m, m intervals
from m to m, m intervals
Mud Logging:
(Riser Holes Only)
Basic Sampling Intervals: 5m
Estimated days: Drilling/Coring:16.6 Logging:2 Total On-Site:18.6
Future Plan: Longterm Borehole Observation Plan/Re-entry Plan
Please check flowing List of Potential Hazards
Shallow GasComplicated GeologicalStructures
Hydrothermal Activity
What is your Weather window?
(Preferable period with the
reasons)
Hydrocarbon Soft Seabed Landslide and Turbidity Current
Shallow Water Flow Irregular Seabed Methane Hydrate
Abnormal Pressure Currents Diapir and Mud Volcano
Man-made Objects Fractured Zone High Temperature
H2S Fault Ice Conditions
Hazards/
Weather:
CO2 High Dip Angle
°C
19
New RevisedPlease fill out information in all gray boxes
Proposal #: 552-full3 Site #: MBF-3A Date Form Submitted: Oct. 2001
Data Type
SSPRequir-ements
ExistsIn DB Details of available data and data that are still to be collected
1High resolutionseismic reflection
Primary Line(s): Location of Site on line (SP or Time only)R/V Sonne Cruise SO 125 Multichannel, 48 ch, GeoB 97-020/027, GI Gun 0.4 l, Watergun 0.16 l,trace# 2900Crossing Lines(s): no
2Deep Penetrationseismic reflection
Primary Line(s): Pre-Site survey data of ODP Leg 116 Location of Site on line (SP or Time only)R/V Sonne Cruise SO 125 Multichannel, 48 chGeoB 97-020/027, seismic signal penetration >2 strace# 2900 (Fig. 8)Crossing Lines(s):
3 Seismic Velocity† SO 125 velocity information (750 m Offset) not yet available,velocity model from Gopala Rao et al. (1997)
4 Seismic Grid no
5a Refraction(surface)
no
5b Refraction(near bottom)
Yes 10°N 88.5°E T9R (J. Curray, Scripps)
6 3.5 kHz yes, digital Parasound Location of Site on line(Time)
7 Swathbathymetry
yes, Hydrosweep
8a Side-lookingsonar (surface)
yes, Hydrosweep scatter amplitudes, 59 beams
8b Side-lookingsonar (bottom)
9 Photographyor Video
10 Heat Flow
11a Magnetics
11b Gravity
12 Sediment cores13 Rock sampling
14a Water current data14b Ice Conditions15 OBS
microseismicity16 Navigation
17 Other
SSP Classification of Site: SSP Watchdog: Date of Last Review:SSP Comments:
X=required; X*=may be required for specific sites; Y=recommended; Y*=may be recommended for specific sites; R=required forre-entry sites; T=required for high temperature environments; † Accurate velocity information is required for holes deeper than400m.
iSAS/IODP Site Summary Forms: Form 2 - Site Survey Detail
20
New Revised
Proposal #: 552-full3 Site #: MBF-3A Date Form Submitted: Oct 2001Water Depth (m): 3620 m Sed. Penetration (m): 1500 m Basement Penetration (m): no
Do you need to use the conical side-entry sub (CSES) at this site? Yes No
Are high temperatures expected at this site? Yes No
Are there any other special requirements for logging at this site? Yes No
If “Yes” Please describe requirements:
What do you estimate the total logging time for this site to be: 2 days
Measurement Type Scientific ObjectiveRelevance
(1=high, 3=Low)
Neutron-Porosity Yes -Fan hydrology 2
Litho-Density Yes - Silt/Clay ratio, clay mineralogy 1
Natural Gamma Ray Yes - Silt/Clay ratio, clay mineralogy 1
Resistivity-Induction Fan hydrology 2
Acoustic Yes - Calibration of seismic velocity
Fan hydrology
1
2
FMS Yes - Sedimentary structure and facies 1
BHTV No
Resistivity-Laterolog No
Magnetic/Susceptibility Yes - Silt/Clay ratio, clay mineralogy 2
Density-Neutron (LWD) No
Resitivity-Gamma Ray
(LWD)
no
Other: Special tools (CORK,
PACKER, VSP, PCS, FWS,
WSP
no
For help in determining logging times, please contact the ODP-LDEO Wireline Logging Services groupat:
[email protected]://www.ldeo.columbia.edu/BRG/brg_home.htmlPhone/Fax: (914) 365-8674 / (914) 365-3182
Note: Sites with greater than 400 m ofpenetration or significant basementpenetration require deployment ofstandard toolstrings.
iSAS/IODP Site Summary Forms: Form 3 - Detailed Logging Plan
21
New RevisedPlease fill out information in all gray boxes
Proposal #: 552-full3 Site #: MBF-3A Date Form Submitted: 1 october 2001
1 Summary of Operations at site:(Example: Triple-APC to refusal, XCB10 m into basement, log as shown onpage 3.)
Single APC to refusal (~200 m)XCB down to 900 mbsfRCB down to 1500 mbsf
2 Based on Previous DSDP/ODPdrilling, list all hydrocarbonoccurrences of greater thanbackground levels. Give natureof show, age and depth of rock:
no
3 From Available information,list all commercial drilling inthis area that produced oryielded significant hydrocarbonshows. Give depths and ages ofhydrocarbon-bearing deposits.
no
4 Are there any indications of gashydrates at this location?
no
5 Are there reasons to expecthydrocarbon accumulations atthis site? Please give details.
no
6 What “special” precautions willbe taken during drilling?
no
7 What abandonment proceduresdo you plan to follow:
no
8 Please list other natural ormanmade hazards which mayeffect ship’s operations:(e.g. ice, currents, cables)
no
9 Summary: What do youconsider the major risks indrilling at this site?
no
iSAS/IODP Site Summary Forms: Form 4 – Pollution & Safety Hazard Summary
New RevisedProposal # 552-Full3 Site #: MBF-3A Date Form Submitted: October 2001
Sub-bottom
depth (m)
Key reflectors,Unconformities,
faults, etcAge
Assumedvelocity(km/sec)
Lithology Paleo-environmentAve. rate of
sedimentaccumulation
(m/My)
Comments
0-660660
660-1100~1100
1100-1500
"M" reflector
"P" reflector
0-10Ma10 Ma ?>10 Ma
Oligocene ?
1.9
1.9
Mud turbidites
Mud turbidites
Turbidites
Deep sea fan
Deep sea fan
Early fan sediments
66
<50 ?
?
iSAS/IODP Site Summary Forms: Form 5 - Lithologic Summary
22
23
iSAS/IODP Site Summary Forms:Form 1 - General Site Information(Submitted with Preliminary Proposal)
Please fill out information in all gray boxes ___New RevisedSection A: Proposal Information
Title of Proposal: Neogene and late Paleogene record of Himalayan orogeny and climate: a transect
across the Middle Bengal Fan.
Date Form
Submitted:1 October 2001
Site Specific
Objectives with
Priority(Must include
general objectives in
proposal)
Depocenter migration
List Previous
Drilling in Area:DSDP Legs 21, 22, ODP Leg 116
Section B: General Site InformationSite Name:
(e.g. SWPAC-01A)MBF-4A If site is a reoccupation
of an old DSDP/ODP
Site, Please include
former Site
Area or Location: Middle Bengal Fan
Latitude:Deg: 8 N Min: 0.4N
Jurisdiction: International/India
Longitude:Deg: 86 E Min: 47.9E
Distance to Land:
Coordinates
System:__WGS 84, _Other ( )
Priority of Site: Primary: X Alt: Water Depth: 3694 m
24
Section C: Operational Information
Sediments Basement
300 mProposed
Penetration:
(m) What is the total sed. thickness? ? > 2000 m
no
Total Penetration: 300 m
General
Lithologies:Mud turbidites
1-APX/XCBCoring Plan:(Specify or Circle)
1-APC VPC* XCB MDCB* PCS RCB Re-entry HRGB
Standard Tools Special Tools LWDNeutron-Porosity Borehole Televiewer Formation Fluid Sampling Density-Neutron
Litho-DensityNuclear Magnetic
Resonance
Borehole Temperature &
PressureResistivity-Gamma Ray
Gamma Ray Geochemical Borehole Seismic Acoustic
Resistivity Side-Wall Core Sampling
Acoustic
Wireline
Logging Plan:
Formation Image Others ( ) Others ( )
Max.Borehole
Temp. :
Expected value (For Riser Drilling)
Cuttings Sampling Intervals
from m to m, m intervals
from m to m, m intervals
Mud Logging:
(Riser Holes Only)
Basic Sampling Intervals: 5m
Estimated days: Drilling/Coring:2.8 Logging:- Total On-Site:2.8
Future Plan: Longterm Borehole Observation Plan/Re-entry Plan
Please check flowing List of Potential Hazards
Shallow GasComplicated GeologicalStructures
Hydrothermal Activity
What is your Weather window?
(Preferable period with the
reasons)
Hydrocarbon Soft Seabed Landslide and Turbidity Current
Shallow Water Flow Irregular Seabed Methane Hydrate
Abnormal Pressure Currents Diapir and Mud Volcano
Man-made Objects Fractured Zone High Temperature
H2S Fault Ice Conditions
Hazards/
Weather:
CO2 High Dip Angle
°C
25
New RevisedPlease fill out information in all gray boxes
Proposal #: 552-full3 Site #: MBF-4A Date Form Submitted: Oct. 2001
Data Type
SSPRequir-ements
ExistsIn DB Details of available data and data that are still to be collected
1High resolutionseismic reflection
Primary Line(s): Location of Site on line (SP or Time only)R/V Sonne Cruise SO 125 Multichannel, 48 ch, GeoB 97-020/027, GI Gun 0.4 l, Watergun 0.16 l,trace# 2900Crossing Lines(s): no
2Deep Penetrationseismic reflection
Primary Line(s): Pre-Site survey data of ODP Leg 116 Location of Site on line (SP or Time only)R/V Sonne Cruise SO 125 Multichannel, 48 chGeoB 97-020/027, seismic signal penetration >2 strace# 2900Crossing Lines(s):
3 Seismic Velocity† SO 125 velocity information (750 m Offset) not yet available,velocity model from Gopala Rao et al. (1997)
4 Seismic Grid no
5a Refraction(surface)
no
5b Refraction(near bottom)
Yes 10°N 88.5°E T9R (J. Curray, Scripps)
6 3.5 kHz yes, digital Parasound Location of Site on line(Time)
7 Swathbathymetry
yes, Hydrosweep
8a Side-lookingsonar (surface)
yes, Hydrosweep scatter amplitudes, 59 beams
8b Side-lookingsonar (bottom)
9 Photographyor Video
10 Heat Flow
11a Magnetics
11b Gravity
12 Sediment cores13 Rock sampling
14a Water current data14b Ice Conditions15 OBS
microseismicity16 Navigation
17 Other
SSP Classification of Site: SSP Watchdog: Date of Last Review:SSP Comments:
X=required; X*=may be required for specific sites; Y=recommended; Y*=may be recommended for specific sites; R=required forre-entry sites; T=required for high temperature environments; † Accurate velocity information is required for holes deeper than400m.
iSAS/IODP Site Summary Forms: Form 2 - Site Survey Detail
26
New Revised
Proposal #: 552-full3 Site #: MBF-4A Date Form Submitted: Oct 2001Water Depth (m): 3694 m Sed. Penetration (m): 300 m Basement Penetration (m): no
Do you need to use the conical side-entry sub (CSES) at this site? Yes No
Are high temperatures expected at this site? Yes No
Are there any other special requirements for logging at this site? Yes No
If “Yes” Please describe requirements:
What do you estimate the total logging time for this site to be:
Measurement Type Scientific ObjectiveRelevance
(1=high, 3=Low)
Neutron-Porosity no
Litho-Density no
Natural Gamma Ray no
Resistivity-Induction no
Acoustic no
FMS no
BHTV no
Resistivity-Laterolog no
Magnetic/Susceptibility no
Density-Neutron (LWD) no
Resitivity-Gamma Ray
(LWD)
no
Other: Special tools (CORK,
PACKER, VSP, PCS, FWS,
WSP
no
For help in determining logging times, please contact the ODP-LDEO Wireline Logging Services groupat:
[email protected]://www.ldeo.columbia.edu/BRG/brg_home.htmlPhone/Fax: (914) 365-8674 / (914) 365-3182
Note: Sites with greater than 400 m ofpenetration or significant basementpenetration require deployment ofstandard toolstrings.
iSAS/IODP Site Summary Forms: Form 3 - Detailed Logging Plan
27
New RevisedPlease fill out information in all gray boxes
Proposal #: 552-full3 Site #: MBF-4A Date Form Submitted: october 2001
1 Summary of Operations at site:(Example: Triple-APC to refusal, XCB10 m into basement, log as shown onpage 3.)
Single APC to refusal (~200 m)XCB down to 300 mbsf
2 Based on Previous DSDP/ODPdrilling, list all hydrocarbonoccurrences of greater thanbackground levels. Give natureof show, age and depth of rock:
no
3 From Available information,list all commercial drilling inthis area that produced oryielded significant hydrocarbonshows. Give depths and ages ofhydrocarbon-bearing deposits.
no
4 Are there any indications of gashydrates at this location?
no
5 Are there reasons to expecthydrocarbon accumulations atthis site? Please give details.
no
6 What “special” precautions willbe taken during drilling?
no
7 What abandonment proceduresdo you plan to follow:
no
8 Please list other natural ormanmade hazards which mayeffect ship’s operations:(e.g. ice, currents, cables)
no
9 Summary: What do youconsider the major risks indrilling at this site?
no
iSAS/IODP Site Summary Forms: Form 4 – Pollution & Safety Hazard Summary
New RevisedProposal # 552-Full3 Site #: MBF-4A Date Form Submitted: October 2001
Sub-bottom
depth (m)
Key reflectors,Unconformities,
faults, etcAge
Assumedvelocity(km/sec)
Lithology Paleo-environmentAve. rate of
sedimentaccumulation
(m/My)
Comments
0-300 0-2/5 Ma 1.9 Mud turbidites Deep sea fan 60-150
iSAS/IODP Site Summary Forms: Form 5 - Lithologic Summary
28
29
iSAS/IODP Site Summary Forms:Form 1 - General Site Information(Submitted with Preliminary Proposal)
Please fill out information in all gray boxes ___New RevisedSection A: Proposal Information
Title of Proposal: Neogene and late Paleogene record of Himalayan orogeny and climate: a transect
across the Middle Bengal Fan.
Date Form
Submitted:1 October 2001
Site Specific
Objectives with
Priority(Must include
general objectives in
proposal)
Depocenter migration
List Previous
Drilling in Area:DSDP Legs 21, 22, ODP Leg 116
Section B: General Site InformationSite Name:
(e.g. SWPAC-01A)MBF-5A If site is a reoccupation
of an old DSDP/ODP
Site, Please include
former Site
Area or Location: Middle Bengal Fan
Latitude:Deg: 8 N Min: 0.4N
Jurisdiction: International/India
Longitude:Deg: 87 E Min: 10.9E
Distance to Land:
Coordinates
System:__WGS 84, _Other ( )
Priority of Site: Primary: X Alt: Water Depth: 3687m
30
Section C: Operational Information
Sediments Basement
300 mProposed
Penetration:
(m) What is the total sed. thickness? ? > 2000 m
no
Total Penetration: 300 m
General
Lithologies:Mud turbidites
1-APX/XCBCoring Plan:(Specify or Circle)
1-APC VPC* XCB MDCB* PCS RCB Re-entry HRGB
Standard Tools Special Tools LWDNeutron-Porosity Borehole Televiewer Formation Fluid Sampling Density-Neutron
Litho-DensityNuclear Magnetic
Resonance
Borehole Temperature &
PressureResistivity-Gamma Ray
Gamma Ray Geochemical Borehole Seismic Acoustic
Resistivity Side-Wall Core Sampling
Acoustic
Wireline
Logging Plan:
Formation Image Others ( ) Others ( )
Max.Borehole
Temp. :
Expected value (For Riser Drilling)
Cuttings Sampling Intervals
from m to m, m intervals
from m to m, m intervals
Mud Logging:
(Riser Holes Only)
Basic Sampling Intervals: 5m
Estimated days: Drilling/Coring:2.8 Logging:- Total On-Site:2.8
Future Plan: Longterm Borehole Observation Plan/Re-entry Plan
Please check flowing List of Potential Hazards
Shallow GasComplicated GeologicalStructures
Hydrothermal Activity
What is your Weather window?
(Preferable period with the
reasons)
Hydrocarbon Soft Seabed Landslide and Turbidity Current
Shallow Water Flow Irregular Seabed Methane Hydrate
Abnormal Pressure Currents Diapir and Mud Volcano
Man-made Objects Fractured Zone High Temperature
H2S Fault Ice Conditions
Hazards/
Weather:
CO2 High Dip Angle
°C
31
New RevisedPlease fill out information in all gray boxes
Proposal #: 552-full3 Site #: MBF-5A Date Form Submitted: Oct. 2001
Data Type
SSPRequir-ements
ExistsIn DB Details of available data and data that are still to be collected
1High resolutionseismic reflection
Primary Line(s): Location of Site on line (SP or Time only)R/V Sonne Cruise SO 125 Multichannel, 48 ch, GeoB 97-020/027, GI Gun 0.4 l, Watergun 0.16 l,trace# 2900Crossing Lines(s): no
2Deep Penetrationseismic reflection
Primary Line(s): Pre-Site survey data of ODP Leg 116 Location of Site on line (SP or Time only)R/V Sonne Cruise SO 125 Multichannel, 48 chGeoB 97-020/027, seismic signal penetration >2 strace# 2900Crossing Lines(s):
3 Seismic Velocity† SO 125 velocity information (750 m Offset) not yet available,velocity model from Gopala Rao et al. (1997)
4 Seismic Grid no
5a Refraction(surface)
no
5b Refraction(near bottom)
Yes 10°N 88.5°E T9R (J. Curray, Scripps)
6 3.5 kHz yes, digital Parasound Location of Site on line(Time)
7 Swathbathymetry
yes, Hydrosweep
8a Side-lookingsonar (surface)
yes, Hydrosweep scatter amplitudes, 59 beams
8b Side-lookingsonar (bottom)
9 Photographyor Video
10 Heat Flow
11a Magnetics
11b Gravity
12 Sediment cores13 Rock sampling
14a Water current data14b Ice Conditions15 OBS
microseismicity16 Navigation
17 Other
SSP Classification of Site: SSP Watchdog: Date of Last Review:SSP Comments:
X=required; X*=may be required for specific sites; Y=recommended; Y*=may be recommended for specific sites; R=required forre-entry sites; T=required for high temperature environments; † Accurate velocity information is required for holes deeper than400m.
iSAS/IODP Site Summary Forms: Form 2 - Site Survey Detail
32
New Revised
Proposal #: 552-full3 Site #: MBF-5A Date Form Submitted: Oct 2001Water Depth (m): 3687 m Sed. Penetration (m): 300 m Basement Penetration (m): no
Do you need to use the conical side-entry sub (CSES) at this site? Yes No
Are high temperatures expected at this site? Yes No
Are there any other special requirements for logging at this site? Yes No
If “Yes” Please describe requirements:
What do you estimate the total logging time for this site to be:
Measurement Type Scientific ObjectiveRelevance
(1=high, 3=Low)
Neutron-Porosity no
Litho-Density no
Natural Gamma Ray no
Resistivity-Induction no
Acoustic no
FMS no
BHTV no
Resistivity-Laterolog no
Magnetic/Susceptibility no
Density-Neutron (LWD) no
Resitivity-Gamma Ray
(LWD)
no
Other: Special tools (CORK,
PACKER, VSP, PCS, FWS,
WSP
no
For help in determining logging times, please contact the ODP-LDEO Wireline Logging Services groupat:
[email protected]://www.ldeo.columbia.edu/BRG/brg_home.htmlPhone/Fax: (914) 365-8674 / (914) 365-3182
Note: Sites with greater than 400 m ofpenetration or significant basementpenetration require deployment ofstandard toolstrings.
iSAS/IODP Site Summary Forms: Form 3 - Detailed Logging Plan
33
New RevisedPlease fill out information in all gray boxes
Proposal #: 552-full3 Site #: MBF-5A Date Form Submitted: october 2001
1 Summary of Operations at site:(Example: Triple-APC to refusal, XCB10 m into basement, log as shown onpage 3.)
Single APC to refusal (~200 m)XCB down to 300 mbsf
2 Based on Previous DSDP/ODPdrilling, list all hydrocarbonoccurrences of greater thanbackground levels. Give natureof show, age and depth of rock:
no
3 From Available information,list all commercial drilling inthis area that produced oryielded significant hydrocarbonshows. Give depths and ages ofhydrocarbon-bearing deposits.
no
4 Are there any indications of gashydrates at this location?
no
5 Are there reasons to expecthydrocarbon accumulations atthis site? Please give details.
no
6 What “special” precautions willbe taken during drilling?
no
7 What abandonment proceduresdo you plan to follow:
no
8 Please list other natural ormanmade hazards which mayeffect ship’s operations:(e.g. ice, currents, cables)
no
9 Summary: What do youconsider the major risks indrilling at this site?
no
iSAS/IODP Site Summary Forms: Form 4 – Pollution & Safety Hazard Summary
Proposal # 552-Full3 Site #: MBF-5A Date Form Submitted: October 2001
Sub-bottom
depth (m)
Key reflectors,Unconformities,
faults, etcAge
Assumedvelocity(km/sec)
Lithology Paleo-environmentAve. rate of
sedimentaccumulation
(m/My)
Comments
0-300 0-2/5 Ma 1.9 Mud turbidites Deep sea fan 60-150
New Revised
iSAS/IODP Site Summary Forms: Form 5 - Lithologic Summary
34
35
iSAS/IODP Site Summary Forms:Form 1 - General Site Information(Submitted with Preliminary Proposal)
Please fill out information in all gray boxes ___New RevisedSection A: Proposal Information
Title of Proposal: Neogene and late Paleogene record of Himalayan orogeny and climate: a transect
across the Middle Bengal Fan.
Date Form
Submitted:1 October 2001
Site Specific
Objectives with
Priority(Must include
general objectives in
proposal)
Depocenter migration
List Previous
Drilling in Area:DSDP Legs 21, 22, ODP Leg 116
Section B: General Site InformationSite Name:
(e.g. SWPAC-01A)MBF-6A If site is a reoccupation
of an old DSDP/ODP
Site, Please include
former Site
Area or Location: Middle Bengal Fan
Latitude:Deg: 8 N Min: 0.4N
Jurisdiction: International/India
Longitude:Deg: 88 E Min: 6.6E
Distance to Land:
Coordinates
System:__WGS 84, _Other ( )
Priority of Site: Primary: X Alt: Water Depth: 3694 m
36
Section C: Operational Information
Sediments Basement
300 mProposed
Penetration:
(m) What is the total sed. thickness? ? > 2000 m
no
Total Penetration: 300 m
General
Lithologies:Mud turbidites
1-APX/XCBCoring Plan:(Specify or Circle)
1-APC VPC* XCB MDCB* PCS RCB Re-entry HRGB
Standard Tools Special Tools LWDNeutron-Porosity Borehole Televiewer Formation Fluid Sampling Density-Neutron
Litho-DensityNuclear Magnetic
Resonance
Borehole Temperature &
PressureResistivity-Gamma Ray
Gamma Ray Geochemical Borehole Seismic Acoustic
Resistivity Side-Wall Core Sampling
Acoustic
Wireline
Logging Plan:
Formation Image Others ( ) Others ( )
Max.Borehole
Temp. :
Expected value (For Riser Drilling)
Cuttings Sampling Intervals
from m to m, m intervals
from m to m, m intervals
Mud Logging:
(Riser Holes Only)
Basic Sampling Intervals: 5m
Estimated days: Drilling/Coring:2.8 Logging:- Total On-Site:2.8
Future Plan: Longterm Borehole Observation Plan/Re-entry Plan
Please check flowing List of Potential Hazards
Shallow GasComplicated GeologicalStructures
Hydrothermal Activity
What is your Weather window?
(Preferable period with the
reasons)
Hydrocarbon Soft Seabed Landslide and Turbidity Current
Shallow Water Flow Irregular Seabed Methane Hydrate
Abnormal Pressure Currents Diapir and Mud Volcano
Man-made Objects Fractured Zone High Temperature
H2S Fault Ice Conditions
Hazards/
Weather:
CO2 High Dip Angle
°C
37
New RevisedPlease fill out information in all gray boxes
Proposal #: 552-full3 Site #: MBF-6A Date Form Submitted: Oct. 2001
Data Type
SSPRequir-ements
ExistsIn DB Details of available data and data that are still to be collected
1High resolutionseismic reflection
Primary Line(s): Location of Site on line (SP or Time only)R/V Sonne Cruise SO 125 Multichannel, 48 ch, GeoB 97-020/027, GI Gun 0.4 l, Watergun 0.16 l,trace# 2900Crossing Lines(s): no
2Deep Penetrationseismic reflection
Primary Line(s): Pre-Site survey data of ODP Leg 116 Location of Site on line (SP or Time only)R/V Sonne Cruise SO 125 Multichannel, 48 chGeoB 97-020/027, seismic signal penetration >2 strace# 2900Crossing Lines(s):
3 Seismic Velocity† SO 125 velocity information (750 m Offset) not yet available,velocity model from Gopala Rao et al. (1997)
4 Seismic Grid no
5a Refraction(surface)
no
5b Refraction(near bottom)
Yes 10°N 88.5°E T9R (J. Curray, Scripps)
6 3.5 kHz yes, digital Parasound Location of Site on line(Time)
7 Swathbathymetry
yes, Hydrosweep
8a Side-lookingsonar (surface)
yes, Hydrosweep scatter amplitudes, 59 beams
8b Side-lookingsonar (bottom)
9 Photographyor Video
10 Heat Flow
11a Magnetics
11b Gravity
12 Sediment cores13 Rock sampling
14a Water current data14b Ice Conditions15 OBS
microseismicity16 Navigation
17 Other
SSP Classification of Site: SSP Watchdog: Date of Last Review:SSP Comments:
X=required; X*=may be required for specific sites; Y=recommended; Y*=may be recommended for specific sites; R=required forre-entry sites; T=required for high temperature environments; † Accurate velocity information is required for holes deeper than400m.
iSAS/IODP Site Summary Forms: Form 2 - Site Survey Detail
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New Revised
Proposal #: 552-full3 Site #: MBF-6A Date Form Submitted: Oct 2001Water Depth (m): 3672 m Sed. Penetration (m): 300 m Basement Penetration (m): no
Do you need to use the conical side-entry sub (CSES) at this site? Yes No
Are high temperatures expected at this site? Yes No
Are there any other special requirements for logging at this site? Yes No
If “Yes” Please describe requirements:
What do you estimate the total logging time for this site to be:
Measurement Type Scientific ObjectiveRelevance
(1=high, 3=Low)
Neutron-Porosity no
Litho-Density no
Natural Gamma Ray no
Resistivity-Induction no
Acoustic no
FMS no
BHTV no
Resistivity-Laterolog no
Magnetic/Susceptibility no
Density-Neutron (LWD) no
Resitivity-Gamma Ray
(LWD)
no
Other: Special tools (CORK,
PACKER, VSP, PCS, FWS,
WSP
no
For help in determining logging times, please contact the ODP-LDEO Wireline Logging Services groupat:
[email protected]://www.ldeo.columbia.edu/BRG/brg_home.htmlPhone/Fax: (914) 365-8674 / (914) 365-3182
Note: Sites with greater than 400 m ofpenetration or significant basementpenetration require deployment ofstandard toolstrings.
iSAS/IODP Site Summary Forms: Form 3 - Detailed Logging Plan
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New RevisedPlease fill out information in all gray boxes
Proposal #: 552-full3 Site #: MBF-6A Date Form Submitted: october 2001
1 Summary of Operations at site:(Example: Triple-APC to refusal, XCB10 m into basement, log as shown onpage 3.)
Single APC to refusal (~200 m)XCB down to 300 mbsf
2 Based on Previous DSDP/ODPdrilling, list all hydrocarbonoccurrences of greater thanbackground levels. Give natureof show, age and depth of rock:
no
3 From Available information,list all commercial drilling inthis area that produced oryielded significant hydrocarbonshows. Give depths and ages ofhydrocarbon-bearing deposits.
no
4 Are there any indications of gashydrates at this location?
no
5 Are there reasons to expecthydrocarbon accumulations atthis site? Please give details.
no
6 What “special” precautions willbe taken during drilling?
no
7 What abandonment proceduresdo you plan to follow:
no
8 Please list other natural ormanmade hazards which mayeffect ship’s operations:(e.g. ice, currents, cables)
no
9 Summary: What do youconsider the major risks indrilling at this site?
no
iSAS/IODP Site Summary Forms: Form 4 – Pollution & Safety Hazard Summary
Proposal # 552-Full3 Site #: MBF-6A Date Form Submitted: October 2001
Sub-bottom
depth (m)
Key reflectors,Unconformities,
faults, etcAge
Assumedvelocity(km/sec)
Lithology Paleo-environmentAve. rate of
sedimentaccumulation
(m/My)
Comments
0-300 0-2/5 Ma 1.9 Mud turbidites Deep sea fan 60-150
New Revised
iSAS/IODP Site Summary Forms: Form 5 - Lithologic Summary
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